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Publication Abstract from PubMed

In Escherichia coli, cell division is driven by the tubulin-like GTPase, FtsZ, which forms the cytokinetic Z-ring. The Z-ring serves as a dynamic platform for the assembly of the multi-protein divisome, which catalyzes membrane cleavage to create equal daughter cells. Several proteins effect FtsZ assembly, thereby providing spatiotemporal control over cell division. One important class of FtsZ interacting/regulatory proteins are the Z-ring associated proteins, Zaps, which typically modulate Z-ring formation by increasing lateral interactions between FtsZ protofilaments. Strikingly, these Zap proteins show no discernable sequence similarity, suggesting that they likely harbor distinct structures and mechanisms. The 19.8 kDa ZapC, in particular, shows no homology to any known protein. To gain insight into ZapC function, we determined its structure to 2.15 Angstrom and performed genetic and biochemical studies. ZapC is a monomer with a heretofore-unseen fold composed of two domains, an N-terminal alpha-beta region and a C-terminal twisted beta-barrel-like domain. The structure contains two pockets, one on each domain. The N-domain pocket is lined with residues previously implicated to be important for ZapC's function as an FtsZ bundler. The adjacent C-domain pocket contains a hydrophobic center surrounded by conserved basic residues. Mutagenesis analyses indicate that this pocket is critical for FtsZ binding. An extensive FtsZ binding surface is consistent with the fact that, unlike many FtsZ regulators, ZapC binds the large FtsZ globular core rather than C-terminal tail and the presence of two adjacent pockets suggests possible mechanisms for ZapC mediated FtsZ bundling.

Structural and functional analyses reveal insights into the molecular properties of the E. coli Z ring stabilizing protein, ZapC.,Schumacher MA, Zeng W, Huang KH, Tchorzewski L, Janakiraman A J Biol Chem. 2015 Dec 10. pii: jbc.M115.697037. PMID:26655719^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.