Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: A bridge to transcription by RNA polymerase. | Journal of Biology BioMed Central Minireview A bridge to transcription by RNA polymerase Craig D Kaplan and Roger D Kornberg Address Department of Structural Biology Stanford University 299 Campus Dr. West Stanford CA 94305 USA. Correspondence Roger D Kornberg. Email kornberg@ Published 2 December 2008 Journal of Biology 2008 7 39 doi jbiol99 The electronic version of this article is the complete one and can be found online at http content 7 10 39 2008 BioMed Central Ltd Abstract A comprehensive survey of single amino-acid substitution mutations critical for RNA polymerase function published in Journal of Biology supports a proposed mechanism for polymerase action in which movement of the polymerase bridge helix promotes transcriptional activity in cooperation with a critical substrate-interaction domain the trigger loop . X-ray crystallographic studies on multisubunit RNA polymerases RNAPs from eukaryotes bacteria and archaea have revealed highly related enzymes with structurally conserved active sites. For eukaryotic and bacterial enzymes crystal structures of transcribing complexes have been solved showing the locations of the DNA template the nascent RNA product and the substrate-binding site. Structural studies have their limitations however which makes a comprehensive functional screen of amino-acid substitutions in domains critical for polymerase action published in Journal of Biology especially useful. The results of the study by Robert Weinzierl s group Tan et al. 1 are in keeping with previous structural work and will be a valuable resource for interpreting future structural single molecule and molecular modeling experiments. Structural information as the foundation for functional studies Initial structural studies on the prokaryotic and eukaryotic enzymes identified a conserved alpha-helical domain termed the bridge helix that spans between two main lobes of the enzyme for a useful bibliography of the structural literature .
