3NXC

Molecular mechanism by which the Escherichia coli nucleoid occlusion factor, SlmA, keeps cytokinesis in check

Summary for 3NXC

• Entry DOI: 10.2210/pdb3nxc/pdb
• Descriptor: HTH-type protein slmA (2 entities in total)
• Functional Keywords: nucleoid occlusion, cell division, tetr family member, dna binding protein
• Biological source: Escherichia coli
• Cellular location: Cytoplasm, nucleoid (By similarity): A1AHH2
• Total number of polymer chains: 1
• Total formula weight: 24321.15

Authors

Tonthat, N.K.,Schumacher, M.A. (deposition date: 2010-07-13, release date: 2011-02-23, Last modification date: 2024-02-21)

Primary citation

Tonthat, N.K.,Arold, S.T.,Pickering, B.F.,Van Dyke, M.W.,Liang, S.,Lu, Y.,Beuria, T.K.,Margolin, W.,Schumacher, M.A.
Molecular mechanism by which the nucleoid occlusion factor, SlmA, keeps cytokinesis in check.
Embo J., 30:154-164, 2011

PubMed Abstract: In Escherichia coli, cytokinesis is orchestrated by FtsZ, which forms a Z-ring to drive septation. Spatial and temporal control of Z-ring formation is achieved by the Min and nucleoid occlusion (NO) systems. Unlike the well-studied Min system, less is known about the anti-DNA guillotining NO process. Here, we describe studies addressing the molecular mechanism of SlmA (synthetic lethal with a defective Min system)-mediated NO. SlmA contains a TetR-like DNA-binding fold, and chromatin immunoprecipitation analyses show that SlmA-binding sites are dispersed on the chromosome except the Ter region, which segregates immediately before septation. SlmA binds DNA and FtsZ simultaneously, and the SlmA-FtsZ structure reveals that two FtsZ molecules sandwich a SlmA dimer. In this complex, FtsZ can still bind GTP and form protofilaments, but the separated protofilaments are forced into an anti-parallel arrangement. This suggests that SlmA may alter FtsZ polymer assembly. Indeed, electron microscopy data, showing that SlmA-DNA disrupts the formation of normal FtsZ polymers and induces distinct spiral structures, supports this. Thus, the combined data reveal how SlmA derails Z-ring formation at the correct place and time to effect NO.

PubMed: 21113127
DOI: 10.1038/emboj.2010.288

Experimental method

X-RAY DIFFRACTION (2.5 Å)