1ecl
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. 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 Page seeded by OCA on Fri May 2 14:56:13 2008