Structural highlights
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
- ↑ 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
- ↑ 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
