title: The CpxRA two-component system is involved in the maintenance of the integrity of the cell envelope in the rumen bacterium Mannheimia succiniciproducens.
abstract: In this study, we characterized the CpxRA two-component signal transduction system of the rumen bacterium Mannheimia succiniciproducens. The truncated form of the CpxA sensor kinase protein without its transmembrane domain was able to autophosphorylate and transphosphorylate the CpxR response regulator protein in vitro. We identified 152 putative target genes for the Cpx system in M. succiniciproducens, which were differentially expressed by more than twofold upon overexpression of the CpxR protein. Genes of a putative 16-gene operon related to the cell wall and lipopolysaccharide biosynthesis were induced strongly upon CpxR overexpression. The promoter region of the first gene of this operon, wecC encoding UDP-N-acetyl-D-mannosaminuronate dehydrogenase, was analyzed and found to contain a sequence homologous to the CpxR box of Escherichia coli. An electrophoretic mobility shift assay showed that the phosphorylated CpxR proteins were able to bind specifically to PCR-amplified DNA fragments containing the promoter sequence of wecC. Furthermore, a cpxR-disrupted mutant strain exhibited increased envelope permeability compared with a wild-type strain. These results suggest that the Cpx system of M. succiniciproducens is involved in the maintenance of the integrity of the cell envelope.
authors.affiliation: Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea.
authors.forename: Seulgi
authors.initials: S
authors.lastname: Yun
authors.forename: Eun-Gyeong
authors.initials: EG
authors.lastname: Lee
authors.forename: Sang-Yoon
authors.initials: SY
authors.lastname: Kim
authors.forename: Jong Moon
authors.initials: JM
authors.lastname: Shin
authors.forename: Won Seok
authors.initials: WS
authors.lastname: Jung
authors.forename: Doo-Byoung
authors.initials: DB
authors.lastname: Oh
authors.forename: Sang Yup
authors.initials: SY
authors.lastname: Lee
authors.forename: Ohsuk
authors.initials: O
authors.lastname: Kwon
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D031121:Mannheimia / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012417:Rumen / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; C085504:CpxR protein, Bacteria; D011494:Protein Kinases; C092472:CpxA protein, bacteria