FIG. 11.

(A) Model for the induction of β-lactamase during development of M. xanthus. (B) Model for the expression of β-lactamase as a function of morphogenesis. We propose that the induction of β-lactamase is an integral step in the development of M. xanthus and that this induction is likely to play a role in the restructuring of peptidoglycan which occurs during the differentiation of spores. See the text for more details. OM, outer membrane; PG, peptidoglycan; IM, inner membrane; MP, muropeptides; R, repressor protein; P, promoter; ppGpp, guanosine 3′-diphosphate 5′-diphosphate.