RRC ID 53682
Author Singh SK, Parveen S, SaiSree L, Reddy M.
Title Regulated proteolysis of a cross-link-specific peptidoglycan hydrolase contributes to bacterial morphogenesis.
Journal Proc Natl Acad Sci U S A
Abstract Bacterial growth and morphogenesis are intimately coupled to expansion of peptidoglycan (PG), an extensively cross-linked macromolecule that forms a protective mesh-like sacculus around the cytoplasmic membrane. Growth of the PG sacculus is a dynamic event requiring the concerted action of hydrolases that cleave the cross-links for insertion of new material and synthases that catalyze cross-link formation; however, the factors that regulate PG expansion during bacterial growth are poorly understood. Here, we show that the PG hydrolase MepS (formerly Spr), which is specific to cleavage of cross-links during PG expansion in Escherichia coli, is modulated by proteolysis. Using combined genetic, molecular, and biochemical approaches, we demonstrate that MepS is rapidly degraded by a proteolytic system comprising an outer membrane lipoprotein of unknown function, NlpI, and a periplasmic protease, Prc (or Tsp). In summary, our results indicate that the NlpI-Prc system contributes to growth and enlargement of the PG sacculus by modulating the cellular levels of the cross-link-cleaving hydrolase MepS. Overall, this study signifies the importance of PG cross-link cleavage and its regulation in bacterial cell wall biogenesis.
Volume 112(35)
Pages 10956-61
Published 2015-9-1
DOI 10.1073/pnas.1507760112
PII 1507760112
PMID 26283368
PMC PMC4568209
MeSH Cross-Linking Reagents / metabolism Escherichia coli / growth & development* Escherichia coli Proteins / metabolism Morphogenesis* N-Acetylmuramoyl-L-alanine Amidase / metabolism* Peptidoglycan / metabolism* Proteolysis
IF 9.412
Times Cited 34
Prokaryotes E. coli