Sandbox Reserved 344: Difference between revisions

← Older edit Newer edit →

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA, Rudi Siegling

@@ Line 7: / Line 7: @@
 =Introduction=
-PhoP is a cytoplasmic response regulator from the two component system PhoP/PhoQ. This system responds mainly to changes in extracellular Mg<sup>2+</sup> concentration and is an important part of the signal pathway leading to a coordinated cell response in gram-negative bacteria such as ''Escherichia coli'' and ''Salmonella enterica''. PhoQ, located across the inner membrane, responds to low Mg<sup>2+</sup> concentration by phosphorylating PhoP. Phosphorylated PhoP forms a homodimer and affects gene expression and other two component systems. Gene regulation is achieved by the increased affinity of the homodimer to the PhoP box, a tandem repeat promoter. The response is organism specific but generally involves survival in low Mg2+ environments and virulence. <ref name = "Bachh2007"> PMID:17545283</ref><ref name = "Groisman"> PMID:11222580</ref>
+The response regulator PhoP from the OmpR/PhoB family of two-component system is responsible for initiating the cellular response to the extracellular concentration of Mg2+ of certain gram-negative bacteria such as ''Escherichia coli'' and ''Salmonella enterica''. A drop in Mg2+ concentration is an indicator to the pathogenic bacteria that it has entered a host cell and needs to react correspondingly. The histidine protein kinase, PhoQ, spanning the inner membrane of the bacteria, senses the lowered Mg2+ concentration and phosphorylates the cytosolic PhoP. PhoP sets a signal cascade in motion, affecting other two component signalling systems and directly regulating gene expression by binding to PhoP boxes on the DNA. PhoP consists of a regulatory domain and an effector domain.<ref name = "Bachh2007"> PMID:17545283</ref><ref name = "Groisman"> PMID:11222580</ref>
+Gene regulation is achieved by the increased affinity of the homodimer to the PhoP box, a tandem repeat promoter. The response is organism specific but generally involves virulence and the survival in an environment with low Mg2+ concentration.
 =Structure=