3E2E

Crystal Structure of an Intermediate Complex of T7 RNAP and 7nt of RNA

Summary for 3E2E

• Entry DOI: 10.2210/pdb3e2e/pdb
• Related: 3E3J
• Descriptor: DNA-directed RNA polymerase, RNA (5'-R(*GP*GP*GP*AP*GP*UP*G)-3'), DNA (31-MER), ... (5 entities in total)
• Functional Keywords: t7 rna polymerase, dna-directed rna polymerase, transcription, nucleotidyltransferase, transferase, transferase-rna-dna complex, transferase/rna/dna
• Biological source: Bacteriophage T7; More
• Total number of polymer chains: 4
• Total formula weight: 122347.60

Authors

Durniak, K.J.,Bailey, S.,Steitz, T.A. (deposition date: 2008-08-05, release date: 2008-11-04, Last modification date: 2024-02-21)

Primary citation

Durniak, K.J.,Bailey, S.,Steitz, T.A.
The structure of a transcribing t7 RNA polymerase in transition from initiation to elongation
Science, 322:553-557, 2008

PubMed Abstract: Structural studies of the T7 bacteriophage DNA-dependent RNA polymerase (T7 RNAP) have shown that the conformation of the amino-terminal domain changes substantially between the initiation and elongation phases of transcription, but how this transition is achieved remains unclear. We report crystal structures of T7 RNAP bound to promoter DNA containing either a 7- or an 8-nucleotide (nt) RNA transcript that illuminate intermediate states along the transition pathway. The amino-terminal domain comprises the C-helix subdomain and the promoter binding domain (PBD), which consists of two segments separated by subdomain H. The structures of the intermediate complex reveal that the PBD and the bound promoter rotate by approximately 45 degrees upon synthesis of an 8-nt RNA transcript. This allows the promoter contacts to be maintained while the active site is expanded to accommodate a growing heteroduplex. The C-helix subdomain moves modestly toward its elongation conformation, whereas subdomain H remains in its initiation- rather than its elongation-phase location, more than 70 angstroms away.

PubMed: 18948533
DOI: 10.1126/science.1163433

Experimental method

X-RAY DIFFRACTION (3 Å)