1Z3E:
reference: 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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