Biology subjects

Dowson, C.

Publications and source records attributed to Dowson, C..

2 recordsLinked to original sources

bioRxiv2020

Structure-based modelling and dynamics of MurM, a Streptococcus pneumoniae penicillin resistance determinant that functions at the cytoplasmic membrane interface

MurM is an aminoacyl-tRNA dependant ligase that aminoacylates the Lipid II peptidoglycan precursor, in the human pathogen Streptococcus pneumoniae. MurM is required for the generation of branched peptidoglycan precursors enabling indirect cross-links in the peptidoglycan and is found to be essential for penicillin resistance. In this study we have solved the X-ray crystal structure of Staphylococcus aureus FemX, an isofunctional homologue of MurM, and used this as a template to generate a homology model of MurM. Using this model, we perform molecular docking and molecular dynamics to examine the interaction of the protein with the phospholipid bilayer and the membrane embedded Lipid II substrate of MurM. Our model suggests that MurM is associated with the major membrane phospholipid cardiolipin, and we confirm this with experimental evidence that the activity of MurM is enhanced by this phospholipid and inhibited by its direct precursor phosphatidylglycerol. This suggests that the spatial association of pneumococcal membrane phospholipids and their impact on MurM activity may be a critical to the final architecture of the peptidoglycan and the expression of clinically relevant penicillin resistance in this pathogen.

biochemistry↗

bioRxiv2017

Touching proteins with virtual bare hands: how to visualize protein-drug complexes and their dynamics in virtual reality

The ability to precisely visualize the atomic geometry of the interactions between a drug and its protein target in structural models is critical in predicting the correct modifications in previously identified inhibitors to create more effective next generation drugs. It is currently common practice among medicinal chemists while attempting the above to access the information contained in three-dimensional structures by using two-dimensional projections, which can preclude disclosure of useful features. A more precise visualization of the three-dimensional configuration of the atomic geometry in the models can be achieved through the implementation of immersive virtual reality (VR). In this work, we present a freely available software pipeline for visualising protein structures through VR. New customer hardware, such as the HTC VO_SCPCAPIVEC_SCPCAP and the OO_SCPCAPCULUSC_SCPCAP RO_SCPCAPIFTC_SCPCAP utilized in this study, are available at reasonable prices. Moreover, we have combined VR visualization with fast algorithms for simulating intramolecular motions of protein flexibility, in an effort to further improve structure-lead drug design by exposing molecular interactions that might be hidden in the less informative static models.

bioinformatics↗