1vcc
From Proteopedia
AMINO TERMINAL 9KDA DOMAIN OF VACCINIA VIRUS DNA TOPOISOMERASE I RESIDUES 1-77, EXPERIMENTAL ELECTRON DENSITY FOR RESIDUES 1-77
Overview
BACKGROUND: Vaccinia virus, a cytoplasmically-replicating poxvirus, encodes a type I DNA topoisomerase that is biochemically similar to eukaryotic-like DNA topoisomerases I, and which has been widely studied as a model topoisomerase. It is the smallest topoisomerase known and is unusual in that it is resistant to the potent chemotherapeutic agent camptothecin. RESULTS: The crystal structure of a 9 kDa amino-terminal fragment of vaccinia virus DNA topoisomerase I has been determined at 1.6 A resolution. The fragment forms a five-stranded, antiparallel beta-sheet with two short alpha-helices and connecting loops. Residues that are conserved between all eukaryotic-like type I topoisomerases are not clustered in particular regions of the structure. CONCLUSIONS: This is the first atomic structure of any region of a eukaryotic-like DNA topoisomerase I. It has provided insights into the structural bases of the phenotypes of some single-site mutants of the intact topoisomerase. The structure has enabled us to study the interactions within a well-folded protein fragment and the camptothecin resistance of the viral topoisomerase.
About this Structure
1VCC is a Single protein structure of sequence from Vaccinia virus. Full crystallographic information is available from OCA.
Reference
Crystal structure of the amino-terminal fragment of vaccinia virus DNA topoisomerase I at 1.6 A resolution., Sharma A, Hanai R, Mondragon A, Structure. 1994 Aug 15;2(8):767-77. PMID:7994576 Page seeded by OCA on Sat May 3 12:21:51 2008
