1zvt
From Proteopedia
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Structure of the E. coli ParC C-terminal domain
Overview
Most bacteria possess two type IIA topoisomerases, DNA gyrase and topo IV, that together help manage chromosome integrity and topology. Gyrase, primarily introduces negative supercoils into DNA, an activity mediated by, the C-terminal domain of its DNA binding subunit (GyrA). Although closely, related to gyrase, topo IV preferentially decatenates DNA and relaxes, positive supercoils. Here we report the structure of the full-length, Escherichia coli ParC dimer at 3.0 A resolution. The N-terminal DNA, binding region of ParC is highly similar to that of GyrA, but the ParC, dimer adopts a markedly different conformation. The C-terminal domain, (CTD) of ParC is revealed to be a degenerate form of the homologous GyrA, CTD, and is anchored to the top of the N-terminal domains in a, configuration different from that thought to occur in gyrase. Biochemical, assays show that the ParC CTD controls the substrate specificity of topo, IV, likely by capturing DNA segments of certain crossover geometries. This, work delineates strong mechanistic parallels between topo IV and gyrase, while explaining how structural differences between the two enzyme, families have led to distinct activity profiles. These findings in turn, explain how the structures and functions of bacterial type IIA, topoisomerases have evolved to meet specific needs of different bacterial, families for the control of chromosome superstructure.
About this Structure
1ZVT is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
The structural basis for substrate specificity in DNA topoisomerase IV., Corbett KD, Schoeffler AJ, Thomsen ND, Berger JM, J Mol Biol. 2005 Aug 19;351(3):545-61. PMID:16023670
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