MUREIN SEGREGATION IN ESCHERICHIA-COLI

Citation
Ma. Depedro et al., MUREIN SEGREGATION IN ESCHERICHIA-COLI, Journal of bacteriology, 179(9), 1997, pp. 2823-2834
Citations number
51
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
ISSN journal
0021-9193
Volume
179
Issue
9
Year of publication
1997
Pages
2823 - 2834
Database
ISI
SICI code
0021-9193(1997)179:9<2823:MSIE>2.0.ZU;2-K
Abstract
Peptidoglycan (murein) segregation has been studied by means of a new labeling method. The method relies on the ability of Escherichia coli cells to incorporate D-Cys into macromolecular murein. The incorporati on depends on a periplasmic amino acid exchange reaction. At low conce ntrations, D-Cys is innocuous to the cell. The distribution of modifie d murein in purified sacculi can be traced and visualized by immunodet ection of the -SH groups by fluorescence and electron microscopy techn iques. Analysis of murein segregation in wild-type and cell division m utant strains revealed that murein in polar caps is metabolically iner t and is segregated in a conservative fashion, Elongation of the saccu lus apparently occurs by diffuse insertion of precursors over the cyli ndrical part of the cell surface, At the initiation of cell division, there is a FtsZ-dependent localized activation of murein synthesis at the potential division sites. Penicillin-binding protein 3 and the pro ducts of the division genes ftsA and ftsQ are dispensable for the acti vation of division sites. As a consequence, under restrictive conditio ns ftsA,ftsI or ftsQ mutants generate filamentous sacculi with rings o f all-new murein at the positions where septa would otherwise develop.