Search bioRxiv⌕ Search

Biology subjects

Caetano-Anolles, G.

Publications and source records attributed to Caetano-Anolles, G..

3 recordsLinked to original sources

Evolution of intrinsic disorder in the structural domains of viral and cellular proteomes

Intrinsically disordered regions are flexible regions that complement the typical structured regions of proteins. Little is known however about their evolution. Here we leverage a comparative and evolutionary genomics approach to analyze intrinsic disorder in the structural domains of thousands of proteomes. Our analysis revealed that viral and cellular proteomes employ similar strategies to increase disorder but achieve different goals. Viral proteomes evolve disorder for economy of genomic material and multifunctionality. On the other hand, cellular proteomes evolve disorder to advance functionality with increasing genomic complexity. Remarkably, phylogenomic analysis of intrinsic disorder showed that ancient domains were ordered and that disorder evolved as a benefit acquired later in evolution. Evolutionary chronologies of domains indexed with disorder levels and distributions across Archaea, Bacteria, Eukarya and viruses revealed six evolutionary phases, the oldest two harboring only ordered and moderate disorder domains and delimiting two universal common ancestors of life. A biphasic spectrum of disorder versus proteome makeup captured the dichotomy in the evolutionary trajectories of viral and cellular ancestors, one following reductive evolution driven by viral spread of molecular wealth and the other following expansive evolutionary trends to advance functionality through massive domain-forming co-option of disordered loop regions. TeaserComparative and evolutionary genomic analyses of the intrinsic disorder of structural domains in thousands of proteomes reveal proteomes increase disorder as a benefit acquired later in evolution to support viral economy and multifunctionality or advanced cellular functionality.

evolutionary biology↗

New Pathways of Mutational Change in SARS-CoV-2 Proteomes Involve Regions of Intrinsic Disorder Important for Virus Replication and Release

The massive worldwide spread of the SARS-CoV-2 virus is fueling the COVID-19 pandemic. Since the first whole-genome sequence was published in January 2020, a growing database of tens of thousands of viral genomes has been constructed. This offers opportunities to study pathways of molecular change in the expanding viral population that can help identify molecular culprits of virulence and virus spread. Here we investigate the genomic accumulation of mutations at various time points of the early pandemic to identify changes in mutationally highly active genomic regions that are occurring worldwide. We used the Wuhan NC_045512.2 sequence as a reference and sampled 15,342 indexed sequences from GISAID, translating them into proteins and grouping them by month of deposition. The per-position amino acid frequencies and Shannon entropies of the coding sequences were calculated for each month, and a map of intrinsic disorder regions and binding sites was generated. The analysis revealed dominant variants, most of which were located in loop regions and on the surface of the proteins. Mutation entropy decreased between March and April of 2020 after steady increases at several sites, including the D614G mutation site of the spike (S) protein that was previously found associated with higher case fatality rates and at sites of the NSP 12 polymerase and the NSP13 helicase proteins. Notable expanding mutations include R203K and G204R of the nucleocapsid (N) protein inter-domain linker region and G251V of the viroporin encoded by ORF3a between March and April. The regions spanning these mutations exhibited significant intrinsic disorder, which was enhanced and decreased by the N-protein and viroporin 3a protein mutations, respectively. These results predict an ongoing mutational shift from the spike and replication complex to other regions, especially to encoded molecules known to represent major {beta}-interferon antagonists. The study provides valuable information for therapeutics and vaccine design, as well as insight into mutation tendencies that could facilitate preventive control.

bioinformatics↗

Paradoxical β-lactamase activity of archaeal encoding enzymes

{beta}-lactams targeting the bacterial cell wall are not active on archaea. Here, we figure out that annotation of genes as {beta}-lactamase in Archeae on the basis of homologous genes, initially annotated {beta}-lactamases, is a remnant of the identification of the original activities of this group of enzymes, which in fact, have multiple functions including nuclease, ribonuclease, {beta}-lactamase, or glyoxalase; which may specialized over time. We expressed a class B {beta}-lactamase enzyme from Methanosarcina barkeri that digest penicillin G. Moreover, while a weak glyoxalase activity was detected, a significant ribonuclease activity on bacterial and synthetic RNAs was demonstrated. The {beta}-lactamase activity was inhibited by a {beta}-lactamase inhibitor (sulbactam), but its RNAse activity was not. This gene appears to has been transferred to the Flavobacteriaceae group including Elizabethkingia genus in which the expressed gene shows a more specialized activity toward resistance to tienanmicin but no glyoxalase activity. The expressed class C-like {beta}-lactamase gene, also from Methanosarcina sp., shows also hydrolysis activity and was more closely related to DD-peptidase enzymes than known bacterial class C {beta}-lactamases. Our findings highlight the requalification needness of annotated enzymes as {beta}-lactamases and the specification overtime of multipotent enzymes in different ways in Archaea and bacteria.

microbiology↗