4xlp
From Proteopedia
Crystal structure of T.aquaticus transcription initiation complex containing upstream fork promoter
Structural highlights
Function[RPOZ_THEAQ] Promotes RNA polymerase assembly. Latches the N- and C-terminal regions of the beta' subunit thereby facilitating its interaction with the beta and alpha subunits.[1] [SIGA_THEAQ] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This sigma factor is the primary sigma factor during exponential growth.[HAMAP-Rule:MF_00963][2] [3] Publication Abstract from PubMedInitiation of transcription is a primary means for controlling gene expression. In bacteria, the RNA polymerase (RNAP) holoenzyme binds and unwinds promoter DNA, forming the transcription bubble of the open promoter complex (RPo). We have determined crystal structures, refined to 4.14 A-resolution, of RPo containing Thermus aquaticus RNAP holoenzyme and promoter DNA that includes the full transcription bubble. The structures, combined with biochemical analyses, reveal key features supporting the formation and maintenance of the double-strand/single-strand DNA junction at the upstream edge of the -10 element where bubble formation initiates. The results also reveal RNAP interactions with duplex DNA just upstream of the -10 element and potential protein/DNA interactions that direct the DNA template strand into the RNAP active site. Addition of an RNA primer to yield a 4 base-pair post-translocated RNA:DNA hybrid mimics an initially transcribing complex at the point where steric clash initiates abortive initiation and sigma(A) dissociation. Structure of a bacterial RNA polymerase holoenzyme open promoter complex.,Bae B, Feklistov A, Lass-Napiorkowska A, Landick R, Darst SA Elife. 2015 Sep 8;4. doi: 10.7554/eLife.08504. PMID:26349032[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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