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).

Summary for 1ECL

Entry DOI	10.2210/pdb1ecl/pdb
Descriptor	ESCHERICHIA COLI TOPOISOMERASE I (2 entities in total)
Functional Keywords	bacterial type i, dna cleavage, strand passage, topoisomerase
Biological source	Escherichia coli
Total number of polymer chains	1
Total formula weight	67326.30
Authors	Lima, C.D.,Wang, J.C.,Mondragon, A. (deposition date: 1995-05-05, release date: 1995-07-31, Last modification date: 2024-02-07)
Primary citation	Lima, C.D.,Wang, J.C.,Mondragon, A. Three-dimensional structure of the 67K N-terminal fragment of E. coli DNA topoisomerase I. Nature, 367:138-146, 1994 Cited by PubMed Abstract: 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. PubMed: 8114910 DOI: 10.1038/367138a0 PDB entries with the same primary citation
Experimental method	X-RAY DIFFRACTION (1.9 Å)

Structure validation