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Publication Abstract from PubMed

During transcription initiation, RNA polymerase (RNAP) binds and unwinds promoter DNA to form an RNAP-promoter open complex. We have determined crystal structures at 2.9 and 3.0 A resolution of functional transcription initiation complexes comprising Thermus thermophilus RNA polymerase, sigma(A), and a promoter DNA fragment corresponding to the transcription bubble and downstream dsDNA of the RNAP-promoter open complex. The structures show that sigma recognizes the -10 element and discriminator element through interactions that include the unstacking and insertion into pockets of three DNA bases, and that RNAP recognizes the -4/+2 region through interactions that include the unstacking and insertion into a pocket of the +2 base. The structures further show that interactions between sigma and template-strand ssDNA preorganize template-strand ssDNA to engage the RNAP active center.

Structural Basis of Transcription Initiation.,Zhang Y, Feng Y, Chatterjee S, Tuske S, Ho MX, Arnold E, Ebright RH Science. 2012 Oct 18. PMID:23086998^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.