Affiliation:
1. Department of Biochemistry, University of Oxford, Oxford, United Kingdom
Abstract
ABSTRACT
MreB is thought to be a bacterial actin homolog that defines the morphology of rod-shaped bacteria.
Rhodobacter sphaeroides
changes shape, from a rod to coccobacillus, and undergoes extensive cytoplasmic membrane invagination when it switches from aerobic to photoheterotrophic growth. The role of MreB in defining
R. sphaeroides
shape was therefore investigated. Attempts at deleting or insertionally inactivating
mreB
were unsuccessful under all growth conditions. Immunofluorescence microscopy showed MreB localized to mid-cell in elongating cells under both aerobic and photoheterotrophic conditions. Three-dimensional reconstruction showed that MreB formed a ring at mid-cell. MreB remained at mid-cell as septation began but localized to new sites in the daughter cells before the completion of septation. MreB localized to putative septation sites in cephalexin-treated filamentous cells. Genomic single-copy
mreB
was replaced with
gfp
-
mreB
, and green fluorescent protein (GFP)-MreB localized in the same pattern, as seen with immunofluorescence microscopy. Some of the cells expressing GFP-MreB were abnormal, principally displaying an increase in cell width, suggesting that the fusion was not fully functional in all cells. GFP-MreB localized to swellings at mid-cell in cells treated with the penicillin-binding protein 2 inhibitor amdinocillin. These data suggest that MreB is essential in
R. sphaeroides
, performing a role at mid-cell in elongating cells, and in early septation, putatively in the cytoplasmic control of the peptidoglycan synthetic complexes.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Cited by
72 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献