Structural highlights
Function
TOP1_MYCTU Releases the supercoiling and torsional tension of DNA, which is 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 a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(5'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 3'-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 3'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone.[HAMAP-Rule:MF_00952][1] The C-terminus (residues 622-934) inhibits RNA cleavage by MazF4.[2]
See Also
References
- ↑ Huang F, He ZG. Characterization of an interplay between a Mycobacterium tuberculosis MazF homolog, Rv1495 and its sole DNA topoisomerase I. Nucleic Acids Res. 2010 Dec;38(22):8219-30. doi: 10.1093/nar/gkq737. Epub 2010, Aug 19. PMID:20724443 doi:http://dx.doi.org/10.1093/nar/gkq737
- ↑ Huang F, He ZG. Characterization of an interplay between a Mycobacterium tuberculosis MazF homolog, Rv1495 and its sole DNA topoisomerase I. Nucleic Acids Res. 2010 Dec;38(22):8219-30. doi: 10.1093/nar/gkq737. Epub 2010, Aug 19. PMID:20724443 doi:http://dx.doi.org/10.1093/nar/gkq737
