Characterization of three putative sub-domains in the signal-input domain of the ArcB hybrid sensor in Escherichia coli(1).
The ArcB sensor plays a crucial role in the histidine to aspartate (His-to-Asp) phosphorelay signal transduction, which is involved in the transcriptional regulatory network that allows Escherichia coli cells to sense various respiratory growth conditions. ArcB is one of the best-studied hybrid His-kinases involved in the multi-step His-to-Asp phosphorelay. However, a major question that remains to be elucidated is: how does ArcB sense an anoxic signal? The N-terminal region of ArcB is considered to be a signal-input domain, which probably plays a role in such signal-perception. In this study, this N-terminal region of ArcB was dissected into three putative sub-domains, a "transmembrane domain," a "leucine-zipper-like domain, " and a "PAS-like domain." The importance of these structural domains was assessed in vivo and in vitro by systematically analyzing a number of arcB mutants, each of which encodes a mutant ArcB protein having an amino acid substitution or a deletion within one of these sub-domains. The results are discussed with special reference to the nature of the ArcB anaerobic sensor.
Matsushika
A
A
Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan.
Mizuno
T
T
D000595:Amino Acid Sequence; D000693:Anaerobiosis; D001426:Bacterial Proteins; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins; D016350:Leucine Zippers; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D011494:Protein Kinases / Q000378:metabolism*; D017433:Protein Structure, Secondary; D015398:Signal Transduction; D000069296:Type III Secretion Systems
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C114344:PAS protein, E coli; D000069296:Type III Secretion Systems; D011494:Protein Kinases; C065271:arcB protein, E coli