1ecl
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AMINO TERMINAL 67KDA DOMAIN OF ESCHERICHIA COLI DNA TOPOISOMERASE I (RESIDUES 2-590 OF MATURE PROTEIN) CLONING ARTIFACT ADDS TWO RESIDUES TO THE AMINO-TERMINUS WHICH WERE NOT OBSERVED IN THE EXPERIMENTAL ELECTRON DENSITY (GLY-2, SER-1).
OverviewOverview
The three-dimensional structure of the 67K amino-terminal fragment of, Escherichia coli DNA topoisomerase I has been determined to 2.2 A, resolution. The polypeptide folds in an unusual way to give four distinct, domains enclosing a hole large enough to accommodate a double-stranded, DNA. The active-site tyrosyl residue, which is involved in the transient, breakage of a DNA strand and the formation of a covalent enzyme-DNA, intermediate, is present at the interface of two domains. The structure, suggests a plausible mechanism by which E. coli DNA topoisomerase I and, other members of the same DNA topoisomerase subfamily could catalyse the, passage of one DNA strand through a transient break in another strand.
About this StructureAbout this Structure
1ECL 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
Three-dimensional structure of the 67K N-terminal fragment of E. coli DNA topoisomerase I., Lima CD, Wang JC, Mondragon A, Nature. 1994 Jan 13;367(6459):138-46. PMID:8114910
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