6xjf
From Proteopedia
X-ray crystal structure of Pyrococcus furiosus general transcription factor TFE-alpha (SeMet labeled protein)
Structural highlights
Function[TFE_PYRFU] Transcription factor that plays a role in the activation of archaeal genes transcribed by RNA polymerase. Facilitates transcription initiation by enhancing TATA-box recognition by TATA-box-binding protein (Tbp), and transcription factor B (Tfb) and RNA polymerase recruitment. Not absolutely required for transcription in vitro, but particularly important in cases where Tbp or Tfb function is not optimal. It dynamically alters the nucleic acid-binding properties of RNA polymerases by stabilizing the initiation complex and destabilizing elongation complexes. Seems to translocate with the RNA polymerase following initiation and acts by binding to the non template strand of the transcription bubble in elongation complexes.[1] [2] Publication Abstract from PubMedOpening of the DNA binding cleft of cellular RNA polymerase (RNAP) is necessary for transcription initiation but the underlying molecular mechanism is not known. Here, we report on the cryo-electron microscopy structures of the RNAP, RNAP-TFEalpha binary, and RNAP-TFEalpha-promoter DNA ternary complexes from archaea, Thermococcus kodakarensis (Tko). The structures reveal that TFEalpha bridges the RNAP clamp and stalk domains to open the DNA binding cleft. Positioning of promoter DNA into the cleft closes it while maintaining the TFEalpha interactions with the RNAP mobile modules. The structures and photo-crosslinking results also suggest that the conserved aromatic residue in the extended winged-helix domain of TFEalpha interacts with promoter DNA to stabilize the transcription bubble. This study provides a structural basis for the functions of TFEalpha and elucidates the mechanism by which the DNA binding cleft is opened during transcription initiation in the stalk-containing RNAPs, including archaeal and eukaryotic RNAPs. Direct binding of TFEalpha opens DNA binding cleft of RNA polymerase.,Jun SH, Hyun J, Cha JS, Kim H, Bartlett MS, Cho HS, Murakami KS Nat Commun. 2020 Nov 30;11(1):6123. doi: 10.1038/s41467-020-19998-x. PMID:33257704[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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