Mechanism of Signalling and Adaptation through the Cytoplasmic Chemoreceptor Cluster.

has two chemotaxis clusters, an -like cluster with membrane-spanning chemoreceptors and a less-understood cytoplasmic cluster. The cytoplasmic CheA is split into CheA, a kinase, and CheA, a His-domain phosphorylated by CheA and a phosphatase domain, which together phosphorylate and dephosphorylate motor-stopping CheY. In bacterial two-hybrid analysis, one major cytoplasmic chemoreceptor, TlpT, interacted with CheA, while the other, TlpC, interacted with CheA.

Genome sequence of Rhodobacter sphaeroides Strain WS8N.

Rhodobacter sphaeroides is a metabolically diverse photosynthetic alphaproteobacterium found ubiquitously in soil and freshwater habitats. Here we present the annotated genome sequence of R. sphaeroides WS8N.

Inducible-expression plasmid for Rhodobacter sphaeroides and Paracoccus denitrificans.

We have developed a stable isopropyl-beta-d-thiogalactopyranoside (IPTG)-inducible-expression plasmid, pIND4, which allows graduated levels of protein expression in the alphaproteobacteria Rhodobacter sphaeroides and Paracoccus denitrificans. pIND4 confers kanamycin resistance and combines the stable replicon of pMG160 with the lacI(q) gene from pYanni3 and the lac promoter, P(A1/04/03), from pJBA24.

Two chemosensory operons of Rhodobacter sphaeroides are regulated independently by sigma 28 and sigma 54.

Rhodobacter sphaeroides has a complex chemosensory system, with several loci encoding multiple homologues of the components required for chemosensing in Escherichia coli. The operons cheOp2 and cheOp3 each encode complete pathways, and both are essential for chemosensing. The components of cheOp2 are predominantly localized to the cell pole, whereas those encoded by cheOp3 are predominantly targeted to a discrete cluster in the cytoplasm.

The CheYs of Rhodobacter sphaeroides.

The Escherichia coli two-component chemosensory pathway has been extensively studied, and its response regulator, CheY, has become a paradigm for response regulators. However, unlike E. coli, most chemotactic nonenteric bacteria have multiple CheY homologues.