Structure and function of a spectrin-like regulator of bacterial cytokinesis.
Bacterial cell division is facilitated by a molecular machine--the divisome--that assembles at mid-cell in dividing cells. The formation of the cytokinetic Z-ring by the tubulin homologue FtsZ is regulated by several factors, including the divisome component EzrA. Here we describe the structure of the 60-kDa cytoplasmic domain of EzrA, which comprises five linear repeats of an unusual triple helical bundle. The EzrA structure is bent into a semicircle, providing the protein with the potential to interact at both N- and C-termini with adjacent membrane-bound divisome components. We also identify at least two binding sites for FtsZ on EzrA and map regions of EzrA that are responsible for regulating FtsZ assembly. The individual repeats, and their linear organization, are homologous to the spectrin proteins that connect actin filaments to the membrane in eukaryotes, and we thus propose that EzrA is the founding member of the bacterial spectrin family.
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
Robert M
RM
Cleverley
Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia.
Jeffrey R
JR
Barrett
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
Arnaud
A
Baslé
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
Nhat Khai
NK
Bui
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
Lorraine
L
Hewitt
NUPPA, Devonshire Building, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
Alexandra
A
Solovyova
Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia.
Zhi-Qiang
ZQ
Xu
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
Richard A
RA
Daniel
Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia.
Nicholas E
NE
Dixon
The ithree Institute, University of Technology, Sydney, New South Wales 2007, Australia.
Elizabeth J
EJ
Harry
Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia.
Aaron J
AJ
Oakley
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
Waldemar
W
Vollmer
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
Richard J
RJ
Lewis
D001412:Bacillus subtilis / Q000737:chemistry / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D048749:Cytokinesis; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D013049:Spectrin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C121014:EzrA protein, Bacillus subtilis; C071525:FtsZ protein, Bacteria; D013049:Spectrin