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Cell division in cocci: localization and properties of the Streptococcus pneumoniae FtsA protein
Author(s) -
Lara Beatriz,
Rico Ana Isabel,
Petruzzelli Sabrina,
Santona Antonella,
Dumas Jacques,
Biton Jacques,
Vicente Miguel,
Mingorance Jesús,
Massidda Orietta
Publication year - 2005
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2004.04432.x
Subject(s) - ftsz , biology , cell division , nucleotide , bacillus subtilis , biochemistry , escherichia coli , adenosine triphosphate , colocalization , microbiology and biotechnology , actin , atp hydrolysis , atpase , biophysics , bacteria , cell , enzyme , genetics , gene
Summary We studied the cytological and biochemical properties of the FtsA protein of Streptococcus pneumoniae . FtsA is a widespread bacterial cell division protein that belongs to the actin superfamily. In Escherichia coli and Bacillus subtilis , FtsA localizes to the septal ring after FtsZ, but its exact role in septation is not known. In S. pneumoniae , we found that, during exponential growth, the protein localizes to the nascent septa, at the equatorial zones of the dividing cells, where an average of 2200 FtsA molecules per cell are present. Likewise, FtsZ was found to localize with the same pattern and to be present at an average of 3000 molecules per cell. Consistent with the colocalization, FtsA was found to interact with FtsZ and with itself. Purified FtsA is able to bind several nucleotides, the affinity being highest for adenosine triphosphate (ATP), and lower for other triphosphates and diphosphates. The protein polymerizes in vitro , in a nucleotide‐dependent manner, forming long corkscrew‐like helixes, composed of 2 + 2 paired protofilaments. No nucleotide hydrolytic activity was detected. Consistent with the absence of an ATPase activity, the polymers are highly stable and not dynamic. These results suggest that the FtsA protein could also polymerize in vivo and the polymers participate in septation.