Structural highlights
Function
[LUXU_VIBHA] Phosphorelay protein which receives sensory signals from LuxN and LuxP and transmits them to LuxO, at low cell density. LuxN and LuxP transfer a phosphoryl group to LuxU on His-58 and this phosphoryl group is further transferred to LuxO. At high cell density, as LuxU could function to establish an equilibrium between the aspartyl-phosphate of LuxN and the aspartyl-phosphate of LuxO, LuxU transfers phosphate from LuxO to LuxN (and probably LuxP) and finally phosphate is drained from the system.[1]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The marine bacterium Vibrio harveyi controls its bioluminescence by a process known as quorum sensing. In this process, autoinducer molecules are detected by membrane-bound sensor kinase/response regulator proteins (LuxN and LuxQ) that relay a signal via a series of protein phosphorylation reactions to another response regulator protein, LuxO. Phosphorylated LuxO indirectly represses the expression of the proteins responsible for bioluminescence. Integral to this quorum sensing process is the function of the phosphotransferase protein, LuxU. LuxU acts to shuttle the phosphate from the membrane-bound proteins, LuxN and LuxQ, to LuxO. LuxU is a 114 amino acid residue monomeric protein. Solution NMR was used to determine the three-dimensional structure of LuxU. LuxU contains a four-helix bundle topology with the active-site histidine residue (His58) located on alpha-helix C and exposed to solution. The active site represents a cluster of positively charged residues located on an otherwise hydrophobic protein face. NMR spin-relaxation experiments identify a collection of flexible residues localized on the same region of LuxU as His58. The studies described here represent the first structural characterization of an isolated, monomeric bacterial phosphotransferase protein.
Solution structure and dynamics of LuxU from Vibrio harveyi, a phosphotransferase protein involved in bacterial quorum sensing.,Ulrich DL, Kojetin D, Bassler BL, Cavanagh J, Loria JP J Mol Biol. 2005 Mar 25;347(2):297-307. PMID:15740742[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Freeman JA, Bassler BL. Sequence and function of LuxU: a two-component phosphorelay protein that regulates quorum sensing in Vibrio harveyi. J Bacteriol. 1999 Feb;181(3):899-906. PMID:9922254
- ↑ Ulrich DL, Kojetin D, Bassler BL, Cavanagh J, Loria JP. Solution structure and dynamics of LuxU from Vibrio harveyi, a phosphotransferase protein involved in bacterial quorum sensing. J Mol Biol. 2005 Mar 25;347(2):297-307. PMID:15740742 doi:10.1016/j.jmb.2005.01.039
