BIOL 82 |
| Transcription Repair Coupling Factor (TRCF, the product of the mfd gene) is a widely conserved bacterial protein that couples DNA repair with transcription. TRCF recognizes RNA polymerase (RNAP) stalled at a non-coding template site of DNA damage, disrupts the transcription complex to release the transcript and enzyme, and recruits the DNA excision repair machinery to the site. The mechanism of RNA release has been illuminated by the discovery that TRCF causes forward translocation of RNAP through an ATP-dependent motor that is homologous to that of the Holliday branch migration protein RecG. TRCF is a large (130 kDa), multi-functional protein with a complex structure/function relationship. In a process involving its ATP-dependent DNA translocase activity, TRCF is able to dissociate the highly stable ternary elongation complex (RNAP/DNA/RNA), resulting in the release of the RNAP and the RNA transcript in a true termination reaction. This is one of only three known mechanisms for transcription termination in bacteria. We will present the 3.2 Å-resolution X-ray crystal structure of TRCF, along with models for its interaction with the RNAP elongation complex. |
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Pfizer Award Symposium: Structure and Function of Macromolecular Assemblies
1:30 PM-4:40 PM, Tuesday, 12 September 2006 Moscone Center -- Room 238, Oral
Division of Biological Chemistry |