1t8b
Crystal structure of refolded PHOU-like protein (gi 2983430) from Aquifex aeolicusCrystal structure of refolded PHOU-like protein (gi 2983430) from Aquifex aeolicus
Structural highlights
FunctionPHOU_AQUAE Plays a role in the regulation of phosphate uptake. In this role, it may bind, possibly as a chaperone, to PhoR, PhoB or a PhoR-PhoB complex to promote dephosphorylation of phospho-PhoB, or inhibit formation of the PhoR-PhoB transitory complex (Probable). Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe phoU gene of Aquifex aeolicus encodes a protein called PHOU_AQUAE with sequence similarity to the PhoU protein of Escherichia coli. Despite the fact that there is a large number of family members (more than 300) attributed to almost all known bacteria and despite PHOU_AQUAE's association with the regulation of genes for phosphate metabolism, the nature of its regulatory function is not well understood. Nearly one-half of these PhoU-like proteins, including both PHOU_AQUAE and the one from E. coli, form a subfamily with an apparent dimer structure of two PhoU domains on the basis of their amino acid sequence. The crystal structure of PHOU_AQUAE (a 221-amino-acid protein) reveals two similar coiled-coil PhoU domains, each forming a three-helix bundle. The structures of PHOU_AQUAE proteins from both a soluble fraction and refolded inclusion bodies (at resolutions of 2.8 and 3.2A, respectively) showed no significant differences. The folds of the PhoU domain and Bag domains (for a class of cofactors of the eukaryotic chaperone Hsp70 family) are similar. Accordingly, we propose that gene regulation by PhoU may occur by association of PHOU_AQUAE with the ATPase domain of the histidine kinase PhoR, promoting release of its substrate PhoB. Other proteins that share the PhoU domain fold include the coiled-coil domains of the STAT protein, the ribosome-recycling factor, and structural proteins like spectrin. Crystal structure of the "PhoU-like" phosphate uptake regulator from Aquifex aeolicus.,Oganesyan V, Oganesyan N, Adams PD, Jancarik J, Yokota HA, Kim R, Kim SH J Bacteriol. 2005 Jun;187(12):4238-44. PMID:15937186[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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