TYPE 1-TOPOISOMERASE CATALYTIC FRAGMENT FROM VACCINIA VIRUSTYPE 1-TOPOISOMERASE CATALYTIC FRAGMENT FROM VACCINIA VIRUS

Structural highlights

1a41 is a 1 chain structure with sequence from Vaccinia virus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.3Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

TOP1_VACCW Releases the supercoiling and torsional tension of DNA introduced during the DNA replication and transcription by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at the specific target site 5'-[CT]CCTTp site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(3'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 5'-OH DNA strand. The free DNA strand then undergoes passage around the unbroken strand thus removing DNA supercoils. Finally, in the religation step, the DNA 5'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone.[1] [2]

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

References

  1. Nagarajan R, Stivers JT. Major groove interactions of vaccinia Topo I provide specificity by optimally positioning the covalent phosphotyrosine linkage. Biochemistry. 2006 May 9;45(18):5775-82. PMID:16669621 doi:http://dx.doi.org/10.1021/bi060133i
  2. Stahley MR, Stivers JT. Mechanism and specificity of DNA strand exchange catalyzed by vaccinia DNA topoisomerase type I. Biochemistry. 2010 Apr 6;49(13):2786-95. PMID:20187656 doi:10.1021/bi902204v

1a41, resolution 2.30Å

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