Biology subjects

Durand, A.

Publications and source records attributed to Durand, A..

At least 19 recordsLinked to original sources

bioRxiv2026

Copper-Mediated Antimicrobial Activity : Targeting Cytochrome c Complexes Across Bacterial Species

Copper (Cu) exerts potent antibacterial activity and contributes to mammalian immune defense. Although solvent exposed 4Fe-4S clusters in cytoplasmic dehydrogenases are major intracellular targets of Cu, its chemical reactivity and subcellular distribution suggest that additional cellular processes may be vulnerable to Cu toxicity. Here, we identify c-type cytochrome biogenesis as a conserved target of Cu excess across diverse pathogenic and environmental bacteria. Analysis of respiratory membrane complexes from pathogens, including Vibrio cholerae and Pseudomonas aeruginosa, revealed pronounced and selective sensitivity of c-type cytochrome-containing complexes to excess Cu. In P. aeruginosa, elevated Cu impaired the cbb3-type cytochrome c oxidase and NapBC-containing cytochrome c complexes while largely sparing complexes independent of c-type cytochromes, including the aa3-type cytochrome c oxidase and succinate dehydrogenase. In contrast, the caa3-type cytochrome c oxidase of Bacillus subtilis, which contains a covalently bound cytochrome c subunit, was also severely affected. Cu likewise depleted c-type cytochromes in plant-associated and photosynthetic bacteria, indicating that this vulnerability is broadly conserved. Complementary analyses in B. subtilis and Escherichia coli showed that Cu primarily disrupts c-type cytochrome assembly rather than promoting the degradation of preassembled complexes. These findings establish c-type cytochrome-containing respiratory complexes as conserved targets of Cu toxicity. Given their central role in electron transport and adaptation to oxygen-limited environments, disruption of cytochrome c biogenesis may contribute to Cu antimicrobial activity and expose a potential vulnerability in pathogens that rely on c-type cytochromes for microaerobic respiration and colonization of hypoxic host tissues.

microbiology↗

bioRxiv2026

MnSOD Diversifies, while FeSOD Dominates Superoxide Defense in Cyanobacteria

Cyanobacteria are unique among prokaryotes in possessing photosynthetic thylakoid membranes enclosing an internal lumen, where superoxide production is expected to be substantial. Thylakoid-associated superoxide dismutases (SODs) would seem the obvious first line of defense, yet many cyanobacteria rely instead on a single soluble cytoplasmic enzyme, raising the question of what role thylakoid-associated SOD isoforms actually play. Using Cyanothece sp. PCC 7425, which encodes both a cytoplasmic FeSOD and a thylakoid-associated MnSOD, we combined sequence analysis, structural, genetics, and biochemical approaches to characterise FeSOD and MnSOD cellular localisation and assess each enzyme's contribution to superoxide defense. Cyanobacterial MnSODs display diverse N-terminal architectures, consistent with soluble, transmembrane, or lipid-anchored forms, yet contribute only modestly to superoxide defense in Cyanothece PCC 7425 and, very likely, across cyanobacteria broadly. Soluble FeSOD instead provides the major line of defense, showing that thylakoid association does not guarantee physiological importance. This predominance of a cytoplasmic enzyme highlights the central role of cytoplasmic superoxide detoxification, consistent with superoxide being generated mainly at the PSI acceptor side, and extends to the chloroplast stroma of plants. Our findings support a model in which SOD distribution reflects metal availability, enzyme properties, and subcellular organisation : FeSOD protects the compartment harbouring the main targets of PSI-associated superoxide, whereas MnSOD is retained where thylakoid association offers additional local protection, but becomes dispensable when the local ROS burden is limited. Spatial matching between superoxide production, antioxidant localisation, and target vulnerability may thus shape the diversification and maintenance of antioxidant systems across cyanobacteria and chloroplasts.

microbiology↗

bioRxiv2026

The Pentose Phosphate Pathway Regulates Myelo-Lymphoid Lineage Specification

Following infection, hematopoietic stem and progenitor cells (HSPCs) support immunity by increasing the rate of innate immune cell production but the metabolic cues that guide this process are unknown. To address this question, we combined in situ RNA barcoding and metabolomics approaches to perform metabolic state-fate mapping in vivo. This approach revealed a subset of myeloid-biased HSPCs that express a distinct set of metabolic enzymes and transporters as well as the surface marker CD62L. Metabolically, CD62Lhigh HSPCs have differential activity of the pentose phosphate pathway (PPP), OXPHOS and translation, as well as differential levels of S-adenosylmethionine (SAM) cycle metabolites associated with epigenetic modifications. Inhibition of the PPP skews HSPC lineage fate decisions by disrupting myeloid associated enhancers, while simultaneously increasing enhancer activity for the master B-lymphoid regulator Ikaros. In vivo, overexpression of glucose-6-phosphate dehydrogenase, a rate limiting enzyme of the PPP, skewed HSPC output from B-lymphocytes. In summary, our data shows that HSPCs undergo significant metabolic changes to facilitate the bioenergetic and epigenetic demands of myeloid versus lymphoid lineage specification. We highlight a key role for the pentose phosphate pathway which modulates myeloid rather than lymphoid commitment by shaping the HSPC enhancer landscape, providing proof of principle that HSPC metabolism can be targeted to modulate immune system dynamics.

immunology↗

bioRxiv2026

Serotonin reuptake inhibition rapidly enhances affect-reward coupling and improves mood over time

Selective serotonin reuptake inhibitors (SSRIs) are widely prescribed antidepressants, yet the mechanisms linking their rapid neurobiological effects to more gradual improvements in mood remain unclear. Computational accounts in which mood reflects the integration of reward outcome and reward prediction errors (RPEs) offer a compelling framework for examining SSRI effects, but reliance on laboratory tasks poses a major translational gap, both in timescale and ecological validity. We address this gap by examining the impact of SSRIs on affect-reward dynamics over a clinically relevant timescale using real-world rewards. Across 11 days, 66 healthy participants (n=37 receiving the SSRI citalopram) completed repeated ecological momentary assessments (EMA) of mood and goal-directed activities (up to 8 per day, totaling 3,542 surveys). By probing anticipated reward (pre-activity) and consummatory reward (post-activity), we derived real-world RPEs to test whether SSRIs amplify RPE impacts on momentary mood. Mixed-effects modelling showed that citalopram rapidly amplified the impact of reward outcome and RPEs on momentary mood, and predicted later increases in positive mood. Citalopram also selectively attenuated the impact of negative mood on expectations for future reward. These findings suggest that SSRIs modulate the bidirectional coupling between mood and reward processes in daily life, consistent with a positive feedback loop that could underpin the gradual mood improvement observed for antidepressant treatment. More broadly, our results highlight the utility of EMA as a highly sensitive real-world assay of early pharmacological effects on mood-reward dynamics.

neuroscience↗

bioRxiv2026

Targeted genome editing of the non-model cyanobacterium Cyanothece PCC 7425 via CRISPR/Cas12a

Cyanobacteria are diverse photosynthetic microorganisms of great interest for fundamental science and sustainable biotechnological applications. However, their polyploidy makes genetic manipulation challenging and time-consuming. The development of CRISPR/Cas tools has greatly accelerated genome editing and metabolic engineering of few cyanobacterial model species. In this work, we extend the CRISPR/Cas12a system for targeted gene deletion in the non-model cyanobacterium Cyanothece PCC 7425, interesting for its ability to perform intracellular calcium carbonate (CaCO3) biomineralization, nitrogen fixation, etc. We demonstrate for the first time its tractability to gene knockout by generating deletion mutants of four genes (cax3-cax4, gor, and sodB) acting in metabolism and/or response to stresses, using Cas12a mediated homologous recombination. Importantly, full chromosome segregation was rapidly achieved after a single round of selection in all cases. All mutants were genotypically and phenotypically characterised. Moreover, biochemical analysis in the case of{Delta} sodB mutant further confirmed its targeted deletion. Overall, CRISRPR/Cas12a provides a rapid and efficient system for genome editing in Cyanothece PCC 7425, establishing this organism as a versatile model for studying oxidative stress pathways, metal toxicity and moreover, the still poorly known mechanism(s) of intracellular CaCO3 biomineralization. Key PointsO_LIRapid and efficient CRISPR/Cas12a editing established in Cyanothece PCC 7425. C_LIO_LIFully segregated knockout mutants obtained after single selection round. C_LIO_LIPlatform for nuclear waste bioremediation and other biotechnological applications. C_LI

microbiology↗

bioRxiv2026

Matched single-cell chromatin, transcriptome, and surface marker profiling captures in vivo epigenomic reprogramming during basal-to-luminal transition in the mammary gland

Single-cell multi-omics methods enable simultaneous mapping of chromatin states and transcriptomes, offering deep insights into gene regulation. Yet, the full potential of these approaches remains untapped for rare cell populations, as most methods require thousands of cells and are limited in their ability to capture multiple molecular layers comprehensively within the same cell. Here, we introduce OneCell CUT&Tag a user-friendly method that provides matched high-resolution epigenome, full-transcriptome, and surface marker quantification from every cell, with input as low as one cell. Using this approach, we uncovered epigenomic priming of basal cells in the mammary gland and captured the dynamics of basal-to-luminal transdifferentiation. We identified a transitional cell population with intermediate epigenomic profiles--absent in reference populations--and demonstrated a continuous epigenomic progression from basal to luminal states, while transcriptomes exhibited a binary switch. Adaptable to diverse samples and tissues, this method also revealed the role of H3K27me3 in shaping zygotic expression programs. By matching multiple layers of molecular information at single-cell resolution, OneCell CUT&Tag dissects the complementary roles of each omics layer in shaping cellular identity and function, opening new avenues to study rare and complex biological systems.

genomics↗

bioRxiv2025

A single-nucleus multimodal framework reveals epigenomic priming of chemoresistant states in ovarian cancer

Non-genetic intratumor heterogeneity (ITH) drives therapeutic failure in cancer, yet its clinical monitoring remains challenging. We develop a multimodal single-nucleus framework that simultaneously profiles transcriptional and histone modification landscapes from frozen biopsies. Applied to longitudinal samples from 16 patients with high-grade serous ovarian cancer (HGSOC), this approach reveals reproducible tumor evolution under chemotherapy: proliferative and interferon-responsive states are lost, while those associated with TNF- and epithelial-mesenchymal transition (EMT) expand. Chromatin profiling shows that these chemoresistant programs are epigenetically primed through H3K4me1 marks before treatment and nominates transcription-factor drivers, including ZBTB7A. Non-genetic baseline tumor composition predicts survival, and fibroblast remodeling parallels malignant adaptation. These findings establish a clinically scalable strategy for mapping functional ITH and identify epigenomic priming as a determinant of therapeutic failure. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=181 HEIGHT=200 SRC="FIGDIR/small/692102v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@432524org.highwire.dtl.DTLVardef@3b7843org.highwire.dtl.DTLVardef@54a2eforg.highwire.dtl.DTLVardef@95273d_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2025

Predicting space use patterns of a territorial top predator: from individual movement decisions to Arctic fox space use

O_LIPredicting animal space use could greatly improve our understanding and forecasting of ecological processes. Despite growing interest, the development of predictive space use models amenable to the integration of spatial processes into ecological frameworks have yet to reach their full potential. C_LIO_LIUsing high-resolution tracking data collected at 4-minute intervals from 26 Arctic foxes over five years, we developed a predictive space use model based on a step-selection approach. We assessed fine-scale habitat selection in relation to prey distribution, landscape features, and ecological constraints such as central place foraging and territoriality. We then used these results to build an agent-based model simulating fox space use and evaluated its ability to reproduce observed space use patterns. C_LIO_LIStep-selection analyses confirmed that fox movements were driven by habitat type, goose nest density, distance to den, and avoidance of distance to the home range boundary. Agent-based simulations closely matched empirical tracking data and accurately forecasted fox space use, even for individuals excluded from model parameterization. C_LIO_LIBy developing a predictive model of predator space-use, our study provides a foundation for incorporating additional components of the predation sequence and contributes to more spatially informed approaches in predator-prey ecology. C_LI

ecology↗

bioRxiv2025

Structural flexibility of the human vault protein revealed by high-resolution cryo-EM and molecular dynamics simulations

Vaults are massive ribonucleoprotein complexes, highly conserved and abundant in eukaryotic cells, yet with unclear function. Their thin-walled barrel-shape architecture is composed of two symmetrical, antiparallel half-shells, each containing 39 copies of the major vault protein (MVP). The spacious lumen of the vault suggests a role in cellular transport. To facilitate cargo encapsulation and release, the vault is thought to open into two halves, yet the molecular mechanism governing vault opening remains elusive. Here, we combine cryogenic electron microscopy (cryo-EM) and multi-scale molecular dynamics (MD) simulations to reveal the structural factors giving flexibility to the human vault protein. Using cryo-EM, we identified two alternative conformational states of the human vault, along with the half-vault shell. MD simulations of these structures show extensive, breathing-like motions, porous solvent-exposed surfaces, and distinct structural variability between conformational states. The stable intermediates and the flexibility at the interface of the half vaults together suggest a possible mechanism for the dynamic assembly and disassembly of the vault.

biochemistry↗

bioRxiv2025

Organisation of axial regions of isolated mitotic chromosomes visualised by cryo correlative light and electron tomography

The formation of mitotic chromosomes is essential for the accurate segregation of genetic material during cell division. Increasing evidence suggests that chromosome formation involves the reorganization of DNA into loops anchored within chromosomal axial regions, whose structural organization remains insufficiently characterized. Taking advantage of DT40 cells, an avian cell model characterized by the presence of a range of chromosome sizes from 3.2-197 Mb, we have established a preparation of entire close-to-native native mitotic chromosomes for cryogenic correlative light and electron microscopy (cryo-CLEM). The size of the smallest chromosomes allows imaging of their axial regions without further thinning. Cryo-electron tomography of the chromosome axial regions reveals the presence of heterogeneous non-histone macromolecular densities (NHMDs), approximately 30-45 nm in size, interspersed within chromatin/DNA regions. We propose that NHMDs may contain condensins and contribute to chromosome architecture. In addition to NHMDs, we identified dense clusters of particles, similar in size, near the chromosome surface, likely associated with ribosomal components. To quantitatively differentiate NHMDs from these surface clusters, we developed an analytical approach based on particle interspacing and spatial distribution within the chromosome volume. By establishing a cryo-CLEM workflow for whole, near-native mitotic chromosomes, our study provides a foundation for investigating their ultrastructural architecture.

cell biology↗

bioRxiv2024

A structural MRI marker predicts individual differences in impulsivity and classifies patients with behavioral-variant frontotemporal dementia from matched controls

Impulsive decision-making is a symptom across many neuropsychiatric and neurological disorders. Yet, it is still unknown whether impulsivity can be predicted based on individual differences in brain structure. Here, we used machine-learning to develop a structural MRI signature of impulsivity, tested its validity in several independent samples, and assessed its diagnostic value in patients with behavioral variant frontotemporal dementia (bvFTD)--a neurodegenerative disease characterized by high impulsivity. The resulting whole-brain grey matter density pattern--the Structural Impulsivity Signature (SIS)--showed a good prediction-outcome correlation of r=0.35 (out-of-sample, p=0.0028) in the training sample of healthy adults (N=117) and significantly predicted individual differences in impulsivity in four other, independent studies (total N=626), including healthy and clinical participants with neuropsychiatric and neurological conditions. Further, the SIS separated bvFTD patients from controls with high accuracy (81% correct, p=0.002) and predicted impulsivity-related symptom severity among patients. The spatial distribution of weights in the SIS brain pattern highlights the key role of brain regions associated with affective processing in impulsivity. Together, these results provide evidence for a new structural neuromarker of individual differences in impulsivity that can be easily applied to new samples. Future studies can further assess its predictive value towards better prevention, diagnosis and treatment of mental disorders associated with impulsivity symptoms.

neuroscience↗

bioRxiv2024

High delay discounting relates to core symptoms and to pulvinar atrophy in frontotemporal dementia

Behavioural variant frontotemporal dementia (bvFTD) is a neurodegenerative disorder characterized by behavioural changes and atrophy in brain regions important for decision-making. Computations such as trading off between larger later (LL) and smaller sooner (SS) rewards -- called delay discounting in behavioural economics -- might be heavily impaired by bvFTD. In this cross-sectional study, our objectives were to investigate (1) whether bvFTD patients show higher delay discounting than healthy controls, (2) whether this maladaptive discounting correlates with impulsivity-related bvFTD symptoms, and (3) in which brain regions atrophy is related to bvFTDs steeper discounting. BvFTD patients (N=24) and matched controls (N=18) performed two delay discounting tasks: one with monetary rewards and one with food rewards. We compared discount rates (log(k)) in bvFTD patients and controls and tested their correlations with symptoms. We used participants structural MRI data and applied whole-brain mediation analyses to investigate brain structures mediating the effect of bvFTD on delay discounting. For both monetary and food rewards, delay discounting was significantly higher in bvFTD patients than in healthy controls. BvFTD patients higher discounting of both money and food was associated with their greater disinhibition and eating behaviour changes. Whole-brain mediation analyses revealed that (1) several brain regions (left thalamic pulvinar, left parahippocampal cortex, right temporal lobe) were predictive of steeper discounting of both money and food and (2) grey matter density in these brain regions, including most prominently the medial pulvinar, mediated the effect of bvFTD on discounting. The impulsive preference for sooner rewards captured by delay discounting might constitute a common mechanism of the behavioural symptoms of inhibition deficit and eating behaviour changes in bvFTD. Future studies could further investigate the potential role of medial pulvinar structural modifications as a transdiagnostic marker and a therapeutic target of impulsivity troubles.

neuroscience↗

bioRxiv2024

Development of AI-assisted microscopy frameworks through realistic simulation in pySTED

The integration of artificial intelligence (AI) into microscopy systems significantly enhances performance, optimizing both the image acquisition and analysis phases. Development of AI-assisted super-resolution microscopy is often limited by the access to large biological datasets, as well as by the difficulties to benchmark and compare approaches on heterogeneous samples. We demonstrate the benefits of a realistic STED simulation platform, pySTED, for the development and deployment of AI-strategies for super-resolution microscopy. The simulation environment provided by pySTED allows the augmentation of data for the training of deep neural networks, the development of online optimization strategies, and the training of reinforcement learning models, that can be deployed successfully on a real microscope.

bioinformatics↗

bioRxiv2023

Knowledge by omission: the significance of omissions in the 5-choice serial reaction time task

The 5-choice serial reaction time task (5-CSRTT) is commonly used to assess attention in rodents. Manipulation of this task by decreasing the light stimulus duration is often used to probe attentional capacity and causes a decrease in accuracy and an increase in omissions. However, although a decrease in response accuracy is commonly interpreted as a decrease in attention, it is more difficult to interpret an increase in omissions in terms of attentional performance. Here we present a series of experiments in rats that seeks to investigate the origins of these key behavioral measures of attention in the 5-CSRTT. After an initial training in the 5-CSRTT, rats were tested in a variable stimulus duration procedure to increase task difficulty and probe visual attentional capacity under several specific controlled conditions. We found that response accuracy reflects visuospatial sustained attentional processing, as commonly interpreted, while response omission reflects rats ignorance about the stimulus location, presumably due to failure to pay attention to the curved wall during its presentation. Moreover, when rats lack of relevant information, they choose not to respond instead of responding randomly. Overall, our results indicate that response accuracy and response omission thus correspond to two distinct attentional states.

animal behavior and cognition↗

bioRxiv2023

The scheduling of adolescence with Netrin-1 and UNC5C

Dopamine axons are the only axons known to grow during adolescence. Here, using rodent models, we examined how two proteins, Netrin-1 and its receptor, UNC5C, guide dopamine axons towards the prefrontal cortex and shape behaviour. We demonstrate in mice (Mus musculus) that dopamine axons reach the cortex through a transient gradient of Netrin-1 expressing cells - disrupting this gradient reroutes axons away from their target. Using a seasonal model (Siberian hamsters; Phodopus sungorus) we find that mesocortical dopamine development can be regulated by a natural environmental cue (daylength) in a sexually dimorphic manner - delayed in males, but advanced in females. The timings of dopamine axon growth and UNC5C expression are always phase-locked. Adolescence is an ill-defined, transitional period; we pinpoint neurodevelopmental markers underlying this period.

neuroscience↗

bioRxiv2022

Chronic stress exposure alters the gut barrier: sex-specific effects on microbiota and jejunum tight junctions

Major depressive disorder (MDD) is the leading cause of disability worldwide. However, 30-50% of patients are unresponsive to commonly prescribed antidepressants, highlighting untapped causal biological mechanisms. Dysfunction in the microbiota-gut-brain axis, the bidirectional communications between the central nervous system and gastrointestinal tract that are modulated by gut microorganisms, has been implicated in MDD pathogenesis. Exposure to chronic stress disrupts blood-brain barrier integrity, still, little is known about intestinal barrier function in these conditions particularly for the small intestine where most food and drug absorption takes place. Thus, here we investigate how chronic social or variable stress, two mouse models of depression, impact the jejunum (JEJ) intestinal barrier in males and females. Mice were subjected to stress paradigms followed by analysis of gene expression profiles of intestinal barrier-related targets, fecal microbial composition, and blood-based markers. Altered microbial populations as well as changes in gene expression of JEJ tight junctions were observed depending on the type and duration of stress, with sex-specific effects. We took advantage of machine learning to characterize in detail morphological tight junction properties identifying a cluster of ruffled junctions in stressed animals. Junctional ruffling is associated with inflammation, so we evaluated if LPS injection recapitulates stress-induced changes in the JEJ and observed profound sex differences. Finally, LPS-binding protein (LBP), a marker of gut barrier leakiness, was associated with stress vulnerability in mice and translational value was confirmed on blood samples from women with MDD. Our results provide evidence that chronic stress disrupts intestinal barrier homeostasis in conjunction with the manifestation of depressive-like behaviors in a sex-specific manner in mice and possibly, human depression.

neuroscience↗

bioRxiv2022

Biodiversity and distribution of sea anemones (Cnidaria, Anthozoa, Actiniaria) in Peru

Diverse and abundant sea anemones are common in shallow marine areas. Detailed biodiversity analysis in Peru are comparatively scarce. To contribute to the biodiversity inventory and distribution information of this taxa, we analyzed exhaustively the available bibliography in Peruvian waters. A total of 23 anemone species were identified, distributed in 68 localities, and grouped into 1 Order (Actiniaria), 6 Families (Actiniidae, Actinostolidae, Aiptasiidae, Isanthidae, Phelliidae and Sagartiidae) and 20 Genera. The most reported species are Anthothoe chilensis (37 references), Phymactis clematis (28), Phymanthea pluvia (27), Oulactis concinnata (18), and Antholoba achates (15). Lima is the region with the highest number of publications, followed by La Libertad, Piura, Lambayeque, and Ancash. Anthothoe chilensis occurs in almost all the Peruvian coastal regions. On the contrary, O. concinnata has been primarily observed in Lima, while A. achates occurred only in the southern regions (Ica, Arequipa, and Moquegua). Rocky substrates (~55% records) seem to be the most suitable habitat for sea anemones in Peru, corresponding to exposed (e.g. vertical walls) and sheltered zones (e.g. rocky crevices, caves, under rock areas). Although most of the species in Peru exhibit a relatively wide spatial distribution, our results suggest that there are several regions with little or no research efforts. Despite a growing study effort over the past 30 years (>50% of biodiversity reported), the current biodiversity status for this group is still unclear. A significant effort is needed to better analyze occurrence patterns and unveil new species regarding a changing environmental scenario with human influence.

ecology↗

bioRxiv2022

Specific conformational dynamics of the ATPase head domains and DNA exit gate mediate the Cohesin ATPase cycle

Cohesin is key to eukaryotic genome organization and acts throughout the cell cycle in an ATP- dependent manner. The molecular mechanisms underlying the Cohesin ATPase activity are poorly understood. Here, we have characterized distinct steps of the human Cohesin ATPase cycle and show that the SMC1A and SMC3 ATPase domains undergo specific but concerted structural rearrangements along this cycle. Specifically, while the proximal coiled coil of the SMC1A ATPase domain remains conformationally stable, that of SMC3 displays an intrinsic flexibility. The ATP-dependent formation of the heterodimeric SMC1A/SMC3 ATPase module (engaged state) favours this flexibility, while it is counteracted by binding of NIPBL and DNA (clamped state). Opening of the SMC3/RAD21 interface (open-engaged state) leads to a stiffening of the SMC3 proximal coiled coil that constricts, together with that of SMC1A, the DNA binding chamber of the ATPase module. Our results reveal that the plasticity of the ATP-dependent interface between the SMC1A and SMC3 ATPase domains enables the structural rearrangements occurring between the engaged, clamped and open-engaged states, while keeping the ATP gate shut.

biochemistry↗