Differential effect of mutational impairment of penicillin-binding proteins 1A and 1B on Escherichia coli strains harboring thermosensitive mutations in the cell division genes ftsA, ftsQ, ftsZ, and pbpB.
AUTOR(ES)
García del Portillo, F
RESUMO
To study the functional differences between penicillin-binding proteins (PBPs) 1A and 1B, as well as their recently postulated involvement in the septation process (F. García del Portillo, M. A. de Pedro, D. Joseleau-Petit, and R. D'Ari, J. Bacteriol. 171:4217-4221, 1989), a series of isogenic strains with mutations in the genes coding for PBP 1A (ponA) or PBP 1B (ponB) or in the cell division-specific genes ftsA, ftsQ, pbpB, and ftsZ was constructed and used as the start point to produce double mutants combining the ponA or ponB characters with mutations in cell division genes. PBP 1A seemed to be unable to preserve cell integrity by itself, requiring the additional activities of PBP 2, PBP 3, and FtsQ. PBP 1B was apparently endowed with a more versatile biosynthetic potential that permitted a substantial enlargement of PBP 1A-deficient cells when PBP 2 or 3 was inhibited or when FtsQ was inactive. beta-Lactams binding to PBP 2 (mecillinam) or 3 (furazlocillin) caused rapid lysis in a ponB background. The lytic effect of furazlocillin to ponB cell division double mutants was suppressed at the restrictive temperature irrespective of the identity of the mutated cell division gene. These results indicate that PBPs 1A and 1B play distinct roles in cell wall synthesis and support the idea of a relevant involvement of PBP 1B in peptidoglycan synthesis at the time of septation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=526905Documentos Relacionados
- Division behavior and shape changes in isogenic ftsZ, ftsQ, ftsA, pbpB, and ftsE cell division mutants of Escherichia coli during temperature shift experiments.
- Regulation of cell division in Escherichia coli K-12: probable interactions among proteins FtsQ, FtsA, and FtsZ.
- Localization of FtsI (PBP3) to the Septal Ring Requires Its Membrane Anchor, the Z Ring, FtsA, FtsQ, and FtsL
- Inhibition of growth of ftsQ, ftsA, and ftsZ mutant cells of Escherichia coli by amplification of a chromosomal region encompassing closely aligned cell division and cell growth genes.
- Inactivation of essential division genes, ftsA, ftsZ, suppresses mutations at sfiB, a locus mediating division inhibition during the SOS response in E. coli.