1cy9
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CRYSTAL STRUCTURE OF THE 30 KDA FRAGMENT OF E. COLI DNA TOPOISOMERASE I. MONOCLINIC FORM
OverviewOverview
DNA topoisomerases are the enzymes responsible for maintaining the topological states of DNA. In order to change the topology of DNA, topoisomerases pass one or two DNA strands through transient single or double strand breaks in the DNA phosphodiester backbone. It has been proposed that both type IA and type II enzymes change conformation dramatically during the reaction cycle in order to accomplish these transformations. In the case of Escherichia coli DNA topoisomerase I, it has been suggested that a 30 kDa fragment moves away from the rest of the protein to create an entrance into the central hole in the protein. Structures of the 30 kDa fragment reveal that indeed this fragment can change conformation significantly. The fragment is composed of two domains, and while the domains themselves remain largely unchanged, their relative arrangement can change dramatically.
About this StructureAbout this Structure
1CY9 is a Single protein structure of sequence from Escherichia coli. Active as DNA topoisomerase, with EC number 5.99.1.2 Full crystallographic information is available from OCA.
ReferenceReference
Conformational changes in E. coli DNA topoisomerase I., Feinberg H, Lima CD, Mondragon A, Nat Struct Biol. 1999 Oct;6(10):918-22. PMID:10504724
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