Abstract
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.
Simulations 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.