DipM links peptidoglycan remodelling to outer membrane organization in Caulobacter

摘要: Cell division in Gram-negative organisms requires coordinated invagination of the multilayered cell envelope such that each daughter receives an intact inner membrane, peptidoglycan (PG) layer and outer membrane (OM). Here, we identify DipM, a putative LytM endopeptidase Caulobacter crescentus, show it plays critical role maintaining architecture during growth division. DipM localized to site FtsZ-dependent manner via its PG-binding LysM domains. Although not essential for viability, DeltadipM cells exhibited gross morphological defects, including widening filamentation, indicating shape maintenance domain. Strikingly, lacking also showed OM blebbing at site, poles along body. Cryo electron tomography sacculi isolated from depleted revealed marked thickening PG as compared wild type, which hypothesize leads loss trans-envelope contacts between components Tol-Pal complex. We conclude is required normal maintain sacculus constant thickness allows connections throughout envelope.