Spherical E. coli due to elevated levels of D-alanine carboxypeptidase

• Published in: Nature (London) 1982-06, Vol.297 (5868), p.702-704
• Main Authors: Markiewicz, Zdzislaw, Broome-Smith, Jennifer K., Schwarz, Uli, Spratt, Brian G.
• Format: Article
• Language: English
• Subjects: Carboxypeptidases - metabolism; Escherichia coli; Escherichia coli - enzymology; Escherichia coli - ultrastructure; Humanities and Social Sciences; Isoenzymes - metabolism; letter; multidisciplinary; Muramoylpentapeptide Carboxypeptidase - metabolism; Peptidoglycan - biosynthesis; Science; Science (multidisciplinary)
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/297702a0

The characteristic shape of bacterial cells is maintained by the strength and form of the murein layer of the cell wall 1 . Thus, rod-shaped bacteria need to synthesize a rod-shaped murein. The shape of the murein may be determined by the properties of the penicillin-binding proteins (PBPs) that catalyse the insertion of murein precursors into the cell wall 2 . In Escherichia coli inhibition of PBPs produces characteristic effects on bacterial morphology. For example, inactivation of PBP 2 results in an inability to synthesize cylindrical murein during cell elongation and the growth of E. coli as spherical cells 2 . We report here that osmotically stable spherical cells of E. coli can also be produced by an increase in the level of PBP 5, a D-alanine carboxypeptidase 3 , and show that these cells, and those produced by inactivation of PBP 2, have the same abnormality in the structure of the newly inserted murein.