The interaction of nocardicin A with the penicillin‐binding proteins of Bacillus megaterium KM
TODD JA., YON JR., ELLAR DJ.
The inhibition of elongation of Bacillus megaterium KM growing in the presence of low concentrations of nocardicin A resulted in the production of osmotically stable, actively dividing coccal‐shaped cells. Saturation of penicillin‐binding proteins 3a and 3b with nocardicin A in vivo at these concentrations was correlated with the inhibition of cell elongation. Analysis of the DD‐carboxypeptidase activity of isolated vegetative membranes of B. megaterium KM in vitro indicated that penicillin‐binding protein 4 is not a DD‐carboxypeptidase under the assay conditions used. Penicillin‐binding proteins were analysed by two‐dimensional gel electrophoresis and the suitability of lysozyme treatment of cells as a method of membrane preparation was investigated with regard to the detection of proteins with highly labile penicillin‐binding activities in vitro.