1jr5
From Proteopedia
| |||||||
| Gene: | asiA (Enterobacteria phage T4) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Solution Structure of the Anti-Sigma Factor AsiA Homodimer
Overview
Anti-sigma factors regulate prokaryotic gene expression through interactions with specific sigma factors. The bacteriophage T4 anti-sigma factor AsiA is a molecular switch that both inhibits transcription from bacterial promoters and phage early promoters and promotes transcription at phage middle promoters through its interaction with the primary sigma factor of Escherichia coli, sigma(70). AsiA is an all-helical, symmetric dimer in solution. The solution structure of the AsiA dimer reveals a novel helical fold for the protomer. Furthermore, the AsiA protomer, surprisingly, contains a helix-turn-helix DNA binding motif, predicting a potential new role for AsiA. The AsiA dimer interface includes a substantial hydrophobic component, and results of hydrogen/deuterium exchange studies suggest that the dimer interface is the most stable region of the AsiA dimer. In addition, the residues that form the dimer interface are those that are involved in binding to sigma(70). The results promote a model whereby the AsiA dimer maintains the active hydrophobic surfaces and delivers them to sigma(70), where an AsiA protomer is displaced from the dimer via the interaction of sigma(70) with the same residues in AsiA that constitute the dimer interface.
About this Structure
1JR5 is a Single protein structure of sequence from Enterobacteria phage t4. Full crystallographic information is available from OCA.
Reference
Solution structure and stability of the anti-sigma factor AsiA: implications for novel functions., Urbauer JL, Simeonov MF, Urbauer RJ, Adelman K, Gilmore JM, Brody EN, Proc Natl Acad Sci U S A. 2002 Feb 19;99(4):1831-5. Epub 2002 Feb 5. PMID:11830637
Page seeded by OCA on Sun Mar 30 21:37:50 2008
