Biology subjects

Muthukumar, V.

Publications and source records attributed to Muthukumar, V..

3 recordsLinked to original sources

bioRxiv2018

Molecular Dynamics Simulation of the E. coli FtsZ

Previous molecular dynamics studies of the FtsZ protein revealed that the protein has high intrinsic flexibility which the crystal structures were unable to reveal. The initial configuration in these studies was based on the available crystal structure data and therefore, the effect of the C-terminal Intrinsically Disordered Region (IDR) of FtsZ could not be observed in these previous studies. Recent investigations have revealed that the C-terminal IDR is crucial for FtsZ assembly in vitro and Z ring formation in vivo. Therefore, in this study, we simulate FtsZ with the IDR.\n\nSimulations of the FtsZ monomer in different nucleotide bound forms (without nucleotide, GTP, GDP) were performed. In the conformations of FtsZ monomer with GTP, GTP binds variably with the protein. Such variable interaction with the monomer has not been observed in any previous simulation studies of FtsZ and not observed in crystal structures. The central helix bends towards the C-terminal domain in the GTP bound form, thus making way for polymerization. Nucleotide dependent small shift/rotation of the C-terminal domain was observed in average structures.

biochemistry↗

bioRxiv2018

Molecular Dynamics simulation of the E. coli FtsZ dimer

FtsZ dimer was studied to gain insights into FtsZ protofilament formation. In a previous simulation study of the M.janaschii dimer it was found that the monomer-monomer contacts in the GDP bound dimer is lower which results in the high curvature of the GDP bound protofilaments. In this study, we have simulated the E.coli FtsZ dimer. The initial structure was obtained from our previous study in which we had simulated the E.coli FtsZ monomer with its C-terminal IDR (Intrinsically Disordered region) built by homology modelling. The M.janaschii FtsZ dimer subunit contacts were used in the initial configuration. Simulations of the dimer were performed with GTP, GDP and ATP. We observed that the C-terminal domain rotates considerably during dimerization. We also observed the different dynamics of the GTP, GDP and ATP bound dimers due to which assembly into straight protofilaments is favoured only in the presence of GTP.

biochemistry↗

bioRxiv2018

Molecular Dynamics Simulations of the FtsZ mutant G105S

In our previous studies we simulated FtsZ monomer and dimer in different nucleotide binding states. In our simulations, we had used the E.coli FtsZ homology model including the FtsZ Intrinsically Disordered Region (IDR). Our simulations revealed that FtsZ dynamics involves a key stage in which GTP binds to monomeric FtsZ and opens its nucleotide binding site which in turn favours polymerization. During dimerization, the C-terminal of the top monomer rotates considerably towards the bottom monomer. Such a rotation of the C-terminal domain leads to capture of the nucleotide by its N-terminal domain. In this study we simulate the FtsZ G105S mutant to see if it may have ATPase activity which was reported in a previous study.

biochemistry↗