1z3e
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Crystal Structure of Spx in Complex with the C-terminal Domain of the RNA Polymerase Alpha Subunit
OverviewOverview
Spx, a global transcription regulator in Bacillus subtilis, interacts with, the C-terminal domain of the alpha subunit (alphaCTD) of RNA polymerase to, control gene expression under conditions of disulfide stress, which is, sensed by disulfide bond formation between Spx residues C10 and C13. Here, we describe the crystal structure of the B. subtilis alphaCTD bound to, oxidized Spx. Analysis of the complex reveals interactions between three, regions of "anti-alpha" Spx and helix alpha1 and the "261" determinant of, alphaCTD. The former contact could disrupt the interaction between, alphaCTD and activator proteins or alter the DNA-bound conformation of, alphaCTD, thereby repressing activator-stimulated transcription. Binding, to the 261 determinant would prevent interaction between alphaCTD and, region 4 of sigma(A). Intriguingly, the Spx disulfide bond is far from the, alphaCTD-Spx interface, suggesting that Spx regulates transcription, allosterically or through the redox-dependent creation or destruction of, binding sites for additional components of the transcription machinery.
About this StructureAbout this Structure
1Z3E is a Protein complex structure of sequences from Bacillus subtilis with SO4 as ligand. Active as DNA-directed RNA polymerase, with EC number 2.7.7.6 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of the Bacillus subtilis anti-alpha, global transcriptional regulator, Spx, in complex with the alpha C-terminal domain of RNA polymerase., Newberry KJ, Nakano S, Zuber P, Brennan RG, Proc Natl Acad Sci U S A. 2005 Nov 1;102(44):15839-44. Epub 2005 Oct 25. PMID:16249335
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