2zbk
From Proteopedia
Crystal structure of an intact type II DNA topoisomerase: insights into DNA transfer mechanisms
Structural highlights
FunctionTOP6A_SACSH Relaxes both positive and negative supercoils and exhibits a strong decatenase and unknotting activity; it cannot introduce DNA supercoils (PubMed:7961685). ATP is absolutely required for DNA cleavage; the nonhydrolyzable analog AMP-PNP generates nicked or linear products from a supercoiled dsDNA substrate. Generates staggered two-nucleotide long 5' overhangs. The enzyme is covalently attached transiently to the 5'-ends of the cleaved strands (PubMed:11485995).[1] [2] 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 PubMedDNA topoisomerases resolve DNA topological problems created during transcription, replication, and recombination. These ubiquitous enzymes are essential for cell viability and are highly potent targets for the development of antibacterial and antitumoral drugs. Type II enzymes catalyze the transfer of a DNA duplex through another one in an ATP-dependent mechanism. Because of its small size and sensitivity to antitumoral drugs, the archaeal DNA topoisomerase VI, a type II enzyme, is an excellent model for gaining further understanding of the organization and mechanism of these enzymes. We present the crystal structure of intact DNA topoisomerase VI bound to radicicol, an inhibitor of human topo II, and compare it to the conformation of the apo-protein as determined by small-angle X-ray scattering in solution. This structure, combined with a wealth of experimental data gathered on these enzymes, allows us to propose a structural model for the two-gate DNA transfer mechanism. Crystal structure of an intact type II DNA topoisomerase: insights into DNA transfer mechanisms.,Graille M, Cladiere L, Durand D, Lecointe F, Gadelle D, Quevillon-Cheruel S, Vachette P, Forterre P, van Tilbeurgh H Structure. 2008 Mar;16(3):360-70. PMID:18334211[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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