The Priority program of the Deutsche Forschungsgemeinschaft (DFG) ‘genome function and gene regulation in archaea’; Forschergruppe FOR 1068/1 (Th422/11-1) established at the University of Regensburg (to S.G. and M.T.); National Institute of Health (NIH to M.S.B.); National Institute of General Medical Sciences (NIGMS) Academic Research Enhancement Award (AREA-1R15GM083306). Funding for open access charge: Funds of the University.
Nucleic Acids Research
Transcription - Genetic, Archaeal proteins - Metabolism, Base sequence - DNA, Molecular Sequence Data
The lower jaws of archaeal RNA polymerase and eukaryotic RNA polymerase II include orthologous subunits H and Rpb5, respectively. The tertiary structure of H is very similar to the structure of the C-terminal domain of Rpb5, and both subunits are proximal to downstream DNA in pre-initiation complexes. Analyses of reconstituted euryarchaeal polymerase lacking subunit H revealed that H is important for open complex formation and initial transcription. Eukaryotic Rpb5 rescues activity of the ΔH enzyme indicating a strong conservation of function for this subunit from archaea to eukaryotes. Photochemical cross-linking in elongation complexes revealed a striking structural rearrangement of RNA polymerase, bringing subunit H near the transcribed DNA strand one helical turn downstream of the active center, in contrast to the positioning observed in preinitiation complexes. The rearrangement of subunits H and A'' suggest a major conformational change in the archaeal RNAP lower jaw upon formation of the elongation complex.
Grünberg, Sebastian, et al. "Rearrangement of the RNA polymerase subunit H and the lower jaw in archaeal elongation complexes." Nucleic acids research 38.6 (2010): 1950-1963.