Changes in peptidoglycan composition and penicillin-binding proteins in slowly growing Escherichia coli.
The composition of peptidoglycan of chemostat-grown cultures of Escherichia coli was investigated as a function of growth rate. As the generation time was lengthened from 0.8 to 13.8 h, there was a decrease in the major monomer (disaccharide tetrapeptide) and dimer (bis-disaccharide tetrapeptide), while disaccharide tripeptide moieties increased to greater than 50% of the total wall. The average chain length became much shorter; lipoprotein density tripled, and the number of unusual diaminopimelyl-diaminopimelic acid crossbridges increased fivefold. As cells grew more slowly, amounts of penicillin-binding proteins (PBPs) 1a-1b complex and 4 decreased, while amounts of PBPs 3 and the 5-6 complex increased. We propose that the chemical composition of E. coli cell walls changes with growth rate in a manner consistent with alterations in the activities of PBPs and cell shape.
Tuomanen
E
E
Rockefeller University, New York, New York 10021.
Cozens
R
R
D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000096:biosynthesis*; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism; D006602:Hexosyltransferases; D007700:Kinetics; D002267:Muramoylpentapeptide Carboxypeptidase / Q000096:biosynthesis*; D046915:Penicillin-Binding Proteins; D010457:Peptidoglycan / Q000302:isolation & purification; D010458:Peptidyl Transferases
D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D010457:Peptidoglycan; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase