1i3q
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RNA POLYMERASE II CRYSTAL FORM I AT 3.1 A RESOLUTION
OverviewOverview
Structures of a 10-subunit yeast RNA polymerase II have been derived from two crystal forms at 2.8 and 3.1 angstrom resolution. Comparison of the structures reveals a division of the polymerase into four mobile modules, including a clamp, shown previously to swing over the active center. In the 2.8 angstrom structure, the clamp is in an open state, allowing entry of straight promoter DNA for the initiation of transcription. Three loops extending from the clamp may play roles in RNA unwinding and DNA rewinding during transcription. A 2.8 angstrom difference Fourier map reveals two metal ions at the active site, one persistently bound and the other possibly exchangeable during RNA synthesis. The results also provide evidence for RNA exit in the vicinity of the carboxyl-terminal repeat domain, coupling synthesis to RNA processing by enzymes bound to this domain.
About this StructureAbout this Structure
1I3Q is a Protein complex structure of sequences from Saccharomyces cerevisiae with and as ligands. This structure supersedes the now removed PDB entry 1EN0. Active as DNA-directed RNA polymerase, with EC number 2.7.7.6 Full crystallographic information is available from OCA.
ReferenceReference
Structural basis of transcription: RNA polymerase II at 2.8 angstrom resolution., Cramer P, Bushnell DA, Kornberg RD, Science. 2001 Jun 8;292(5523):1863-76. Epub 2001 Apr 19. PMID:11313498
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