RRC ID 53707
Author Meeske AJ, Sham LT, Kimsey H, Koo BM, Gross CA, Bernhardt TG, Rudner DZ.
Title MurJ and a novel lipid II flippase are required for cell wall biogenesis in Bacillus subtilis.
Journal Proc. Natl. Acad. Sci. U.S.A.
Abstract Bacterial surface polysaccharides are synthesized from lipid-linked precursors at the inner surface of the cytoplasmic membrane before being translocated across the bilayer for envelope assembly. Transport of the cell wall precursor lipid II in Escherichia coli requires the broadly conserved and essential multidrug/oligosaccharidyl-lipid/polysaccharide (MOP) exporter superfamily member MurJ. Here, we show that Bacillus subtilis cells lacking all 10 MOP superfamily members are viable with only minor morphological defects, arguing for the existence of an alternate lipid II flippase. To identify this factor, we screened for synthetic lethal partners of MOP family members using transposon sequencing. We discovered that an uncharacterized gene amj (alternate to MurJ; ydaH) and B. subtilis MurJ (murJBs; formerly ytgP) are a synthetic lethal pair. Cells defective for both Amj and MurJBs exhibit cell shape defects and lyse. Furthermore, expression of Amj or MurJBs in E. coli supports lipid II flipping and viability in the absence of E. coli MurJ. Amj is present in a subset of gram-negative and gram-positive bacteria and is the founding member of a novel family of flippases. Finally, we show that Amj is expressed under the control of the cell envelope stress-response transcription factor σ(M) and cells lacking MurJBs increase amj transcription. These findings raise the possibility that antagonists of the canonical MurJ flippase trigger expression of an alternate translocase that can resist inhibition.
Volume 112(20)
Pages 6437-42
Published 2015-5-19
DOI 10.1073/pnas.1504967112
PII 1504967112
PMID 25918422
PMC PMC4443310
MeSH Bacillus subtilis / enzymology* Bacillus subtilis / growth & development* Bacterial Proteins / metabolism* Cell Wall / physiology* Chromatography, High Pressure Liquid Gene Expression Regulation, Bacterial / physiology* Microscopy, Fluorescence Morphogenesis / physiology* Phospholipid Transfer Proteins / metabolism* Phylogeny Plasmids / genetics Uridine Diphosphate N-Acetylmuramic Acid / analogs & derivatives Uridine Diphosphate N-Acetylmuramic Acid / metabolism
IF 9.58
Prokaryotes E. coli