Structural basis of transcription initiation.
Article Details
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Zhang Y, Feng Y, Chatterjee S, Tuske S, Ho MX, Arnold E, Ebright RH
Structural basis of transcription initiation.
Science. 2012 Nov 23;338(6110):1076-80. doi: 10.1126/science.1227786. Epub 2012 Oct 18.
- PubMed ID
- 23086998 [ View in PubMed]
- Abstract
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 double-stranded DNA 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 single-stranded DNA (ssDNA) preorganize template-strand ssDNA to engage the RNAP active center.