PROSITE documentation PDOC00159

Eukaryotic DNA topoisomerase I active site




Description

DNA topoisomerase I (EC 5.99.1.2) [1,2,3,4] is one of the two types of enzyme that catalyze the interconversion of topological DNA isomers. Type I topoisomerases act by catalyzing the transient breakage of DNA, one strand at a time, and the subsequent rejoining of the strands. When a eukaryotic type 1 topoisomerase breaks a DNA backbone bond, it simultaneously forms a protein-DNA link where the hydroxyl group of a tyrosine residue is joined to a 3'-phosphate on DNA, at one end of the enzyme-severed DNA strand. In eukaryotes and poxvirus topoisomerases I, there are a number of conserved residues in the region around the active site tyrosine.

Last update:

December 2001 / Text revised.

Technical section

PROSITE method (with tools and information) covered by this documentation:

TOPOISOMERASE_I_EUK, PS00176; Eukaryotic DNA topoisomerase I active site  (PATTERN)


References

1AuthorsSternglanz R.
TitleDNA topoisomerases.
SourceCurr. Opin. Cell Biol. 1:533-535(1989).
PubMed ID2560656

2AuthorsSharma A., Mondragon A.
TitleDNA topoisomerases.
SourceCurr. Opin. Struct. Biol. 5:39-47(1995).
PubMed ID7773745

3AuthorsLynn R.M., Bjornsti M.-A., Caron P.R., Wang J.C.
TitlePeptide sequencing and site-directed mutagenesis identify tyrosine-727 as the active site tyrosine of Saccharomyces cerevisiae DNA topoisomerase I.
SourceProc. Natl. Acad. Sci. U.S.A. 86:3559-3563(1989).
PubMed ID2542938

4AuthorsRoca J.
TitleThe mechanisms of DNA topoisomerases.
SourceTrends Biochem. Sci. 20:156-160(1995).
PubMed ID7770916



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