1a36

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spinqualitylabelsall models PDB ID 1a36 Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
1a36, resolution 2.80Å ()
Activity:	DNA topoisomerase, with EC number 5.99.1.2
Structural annotation: Resources: CATH : 1A36A03, 1A36A02, 1A36A01, 1A36A04 InterPro : Ipr011010, Ipr009054, Ipr013500, Ipr013499, Ipr001631, Ipr013030, Ipr008336, Ipr014727, Ipr014711 Pfam : PF02919, PF01028 SCOP : d1a36a2, d1a36a1, d1a36a3 UniProt : P11387
Functional annotation: Cellular component: nucleolus perikaryon chromosome nucleoplasm cytoplasm nucleus Biological process: DNA unwinding during replication response to drug embryonic cleavage phosphorylation DNA topological change programmed cell death DNA replication Molecular function: DNA topoisomerase activity DNA topoisomerase (ATP-hydrolyzing) activity DNA binding chromatin binding protein binding isomerase activity DNA topoisomerase type I activity
Evolutionary conservation: Toggle Conservation Colors: Rows = identical sequences: Further Information: Caveats, Explanation, Complete Results at ConSurfDB
Resources:	FirstGlance, OCA, RCSB, PDBsum
Coordinates:	save as pdb, mmCIF, xml

TOPOISOMERASE I/DNA COMPLEX

Overview

The three-dimensional structure of a 70-kilodalton amino terminally truncated form of human topoisomerase I in complex with a 22-base pair duplex oligonucleotide, determined to a resolution of 2.8 angstroms, reveals all of the structural elements of the enzyme that contact DNA. The linker region that connects the central core of the enzyme to the carboxyl-terminal domain assumes a coiled-coil configuration and protrudes away from the remainder of the enzyme. The positively charged DNA-proximal surface of the linker makes only a few contacts with the DNA downstream of the cleavage site. In combination with the crystal structures of the reconstituted human topoisomerase I before and after DNA cleavage, this information suggests which amino acid residues are involved in catalyzing phosphodiester bond breakage and religation. The structures also lead to the proposal that the topoisomerization step occurs by a mechanism termed "controlled rotation."

About this Structure

1A36 is a Single protein structure of sequence from Homo sapiens. The following page contains interesting information on the relation of 1A36 with [Topoisomerases]. Full crystallographic information is available from OCA.

Reference

A model for the mechanism of human topoisomerase I., Stewart L, Redinbo MR, Qiu X, Hol WG, Champoux JJ, Science. 1998 Mar 6;279(5356):1534-41. PMID:9488652 Page seeded by OCA on Fri May 2 09:44:33 2008