FEATURES

DESCRIPTION

Also known as CPXA_ECOLI, cpxA, ecfB, eup, ssd. Histidine kinase member of the two-component regulatory system CpxA/CpxR which responds to envelope stress response by activating expression of downstream genes including cpxP, degP, dsbA and ppiA (PubMed:7883164, PubMed:9401031, PubMed:9473036). Activates CpxR by phosphorylation; has autokinase, phosphotransferase and (in the presence of Mg(2+) and/or ATP or ADP) phosphatase activity (PubMed:9401031, PubMed:17259177, PubMed:24492262). The kinase activity is inhibited by periplasmic accessory protein CpxP; proteolysis of CpxP relieves inhibition (PubMed:16166523, PubMed:17259177, PubMed:25207645). Involved in several diverse cellular processes, including the functioning of acetohydroxyacid synthetase I, the biosynthesis of isoleucine and valine, the TraJ protein activation activity for tra gene expression in F plasmid (PubMed:8432716), and the synthesis, translocation, or stability of cell envelope proteins (PubMed:7883164). Activates transcription of periplasmic protease degP, probably by phosphorylating the cognate response protein CpxR; overexpression of an outer membrane lipoprotein NlpE also leads to transcription of degP via CpxRA (PubMed:7883164). Required for efficient binding of stationary phase cells to hydrophobic surfaces, part of the process of biofilm formation (PubMed:11830644). The isolated cytoplasmic domain (residues 188-457) crystallizes as a homodimer, and forms dimers of dimers in solution which may be catalytically important (PubMed:24492262). Interacts with periplasmic accessory protein CpxP (PubMed:16166523, PubMed:21317318, PubMed:21239493, PubMed:25207645); interaction with CpxP is not seen in vivo when cells are grown in 0.3 M NaCl, or if the misfolded P pili protein PapE is overexpressed (PubMed:25207645). Interacts with cognate response regulator CpxR (PubMed:25207645).

EXTERNAL LINKS

cpxA

Sensor histidine kinase CpxA

cpxA

Molecular Synopsis