2be5
Crystal structure of the T. Thermophilus RNA polymerase holoenzyme in complex with inhibitor tagetitoxinCrystal structure of the T. Thermophilus RNA polymerase holoenzyme in complex with inhibitor tagetitoxin
Structural highlights
FunctionRPOZ_THET8 Promotes RNA polymerase assembly. Latches the N- and C-terminal regions of the beta' subunit thereby facilitating its interaction with the beta and alpha subunits (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedTagetitoxin (Tgt) inhibits transcription by an unknown mechanism. A structure at a resolution of 2.4 A of the Thermus thermophilus RNA polymerase (RNAP)-Tgt complex revealed that the Tgt-binding site within the RNAP secondary channel overlaps that of the stringent control effector ppGpp, which partially protects RNAP from Tgt inhibition. Tgt binding is mediated exclusively through polar interactions with the beta and beta' residues whose substitutions confer resistance to Tgt in vitro. Importantly, a Tgt phosphate, together with two active site acidic residues, coordinates the third Mg(2+) ion, which is distinct from the two catalytic metal ions. We show that Tgt inhibits all RNAP catalytic reactions and propose a mechanism in which the Tgt-bound Mg(2+) ion has a key role in stabilization of an inactive transcription intermediate. Remodeling of the active site by metal ions could be a common theme in the regulation of catalysis by nucleic acid enzymes. Structural basis for transcription inhibition by tagetitoxin.,Vassylyev DG, Svetlov V, Vassylyeva MN, Perederina A, Igarashi N, Matsugaki N, Wakatsuki S, Artsimovitch I Nat Struct Mol Biol. 2005 Dec;12(12):1086-93. Epub 2005 Nov 6. PMID:16273103[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
|
| ||||||||||||||||||