1T8B: Crystal Structure Of Refolded Phou-like Protein (gi 2983430) From Aquifex Aeolicus

The 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.
PDB ID: 1T8BDownload
MMDB ID: 30885
PDB Deposition Date: 2004/5/11
Updated in MMDB: 2012/12
Experimental Method:
x-ray diffraction
Resolution: 3.23  Å
Source Organism:
Similar Structures:
Biological Unit for 1T8B: monomeric; determined by author and by software (PQS)
Molecular Components in 1T8B
Label Count Molecule
Protein (1 molecule)
Phosphate Transport System Protein Phou Homolog(Gene symbol: phoU)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB