Variability in the posttranslational processing of penicillin-binding protein 1b among different strains of Escherichia coli.

Screening of a number of unrelated strains of Escherichia coli confirms the existence of at least two patterns of molecular forms for penicillin-binding protein 1b in E. coli cell envelopes. Our data support that the beta-form of this protein is produced by posttranslational modification of the alpha-form and suggest that the absence of the beta-form in some strains is due to a strain-dependent variability in the alpha-form processing mechanism.