Growth and division of Streptococcus pneumoniae: localization of the high molecular weight penicillin-binding proteins during the cell cycle.
The bacterial peptidoglycan, the main component of the cell wall, is synthesized by the penicillin-binding proteins (PBPs). We used immunofluorescence microscopy to determine the cellular localization of all the high molecular weight PBPs of the human pathogen Streptococcus pneumoniae, for a wild type and for several PBP-deficient strains. Progression through the cell cycle was investigated by the simultaneous labelling of DNA and the FtsZ protein. Our main findings are: (i) the temporal dissociation of cell wall synthesis, inferred by the localization of PBP2x and PBP1a, from the constriction of the FtsZ-ring; (ii) the localization of PBP2b and PBP2a at duplicated equatorial sites indicating the existence of peripheral peptidoglycan synthesis, which implies a similarity between the mechanism of cell division in bacilli and streptococci; (iii) the abnormal localization of some class A PBPs in PBP-defective mutants which may explain the apparent redundancy of these proteins in S. pneumoniae.
Morlot
Cécile
C
Institut de Biologie Structurale J. -P. Ebel (CEA/CNRS/UJF, UMR 5075), 41 rue Jules Horowitz, 38027 Grenoble Cedex 1, France.
Zapun
André
A
Dideberg
Otto
O
Vernet
Thierry
T
D019881:Aminoacyltransferases; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D016764:Cell Polarity; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006602:Hexosyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D002267:Muramoylpentapeptide Carboxypeptidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D046915:Penicillin-Binding Proteins; D010453:Peptide Synthases; D010457:Peptidoglycan / Q000378:metabolism; D010458:Peptidyl Transferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D013296:Streptococcus pneumoniae / Q000254:growth & development / Q000378:metabolism*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D046915:Penicillin-Binding Proteins; D010457:Peptidoglycan; C478699:penicillin-binding protein 2a, Streptococcus; D019881:Aminoacyltransferases; C478701:penicillin-binding protein 2b, Streptococcus; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D010453:Peptide Synthases