Crystal structure of Mycobacterium tuberculosis Topoisomerase ICrystal structure of Mycobacterium tuberculosis Topoisomerase I

Structural highlights

5d5h is a 1 chain structure with sequence from Mycobacterium tuberculosis H37Rv. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.52Å
Ligands:, ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

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

  1. 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
  2. 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

5d5h, resolution 2.52Å

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