1yua
From Proteopedia
| |||||||
| Activity: | DNA topoisomerase, with EC number 5.99.1.2 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
C-TERMINAL DOMAIN OF ESCHERICHIA COLI TOPOISOMERASE I
Overview
Escherichia coli DNA topoisomerase I catalyzes the interconversion of different topological forms of DNA. In this paper we describe NMR studies of a 14K C-terminal fragment of this enzyme that binds preferentially to single-stranded DNA and enhances the enzyme's ability to relax negatively supercoiled DNA under high salt conditions. The 1H, 13C, and 15N resonances of the protein were assigned from a number of heteronuclear multidimensional NMR experiments, and the three-dimensional structure of the protein was determined from a total of 2188 NMR-derived restraints. The root-mean-square deviation about the mean coordinate positions for residues 13-120 is 0.68 +/- 0.11 A for the backbone atoms and 1.09 +/- 0.09 A for all heavy atoms. The overall fold, which consists of two four-stranded beta-sheets separated by two helices, differs from other DNA- and RNA-binding proteins such as gene 5, cold shock protein, and hnRNP C. From an analysis of the changes in chemical shift upon the addition of single-stranded DNA, the location of the oligonucleotide binding site was determined. The binding site consists of a beta-sheet containing positively charged and aromatic amino acids and, in spite of its different structure, is similar to that found in other proteins that bind single-stranded oligonucleotides.
About this Structure
1YUA is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Solution structure of the C-terminal single-stranded DNA-binding domain of Escherichia coli topoisomerase I., Yu L, Zhu CX, Tse-Dinh YC, Fesik SW, Biochemistry. 1995 Jun 13;34(23):7622-8. PMID:7779808
Page seeded by OCA on Mon Mar 31 01:22:50 2008
