Requirements for noncovalent binding of vaccinia topoisomerase I to duplex DNA Journal Article


Authors: Sekiguchi, J.; Shuman, S.
Article Title: Requirements for noncovalent binding of vaccinia topoisomerase I to duplex DNA
Abstract: Vaccinia DNA topoisomerase binds duplex DNA and forms a covalent adduct at sites containing a conserved sequence element 5'(C/T)CCTT' In the scissile strand. Distinctive aspects of noncovalent versus covalent interaction emerge from analysis of the binding properties of Topo(Phe-274), a mutated protein which is unable to cleave DNA, but which binds DNA noncovalently. Whereas DNA cleavage by wild type enzyme is most efficient with 'suicide' substrates containing fewer than 10 base pairs distal to the scissile bond, optimal noncovalent binding by Topo (Phe-274) requires at least 10-bp of DNA 3' of the cleavage site. Thus, the region of DNA flanking the pentamer motif serves to stabilize the noncovalent topoisomerase - DNA complex. This result is consistent with the downstream dimensions of the DNA binding site deduced from nuclease footprintlng. Topo(Phe-274) binds to duplex DNA lacking the consensus pentamer with 7- 10-fold lower affinity than to CCCTT-containing DNA. © 1994 Oxford University Press.
Keywords: mutation; dna-binding proteins; nonhuman; mutant protein; dna; double stranded dna; conserved sequence; molecular sequence data; substrate specificity; vaccinia virus; base sequence; dna adduct; dna flanking region; binding sites; dna binding; genetic conservation; dna cleavage; dna topoisomerase; dna topoisomerases, type i; covalent bond; priority journal; article; support, u.s. gov't, p.h.s.
Journal Title: Nucleic Acids Research
Volume: 22
Issue: 24
ISSN: 0305-1048
Publisher: Oxford University Press  
Date Published: 1994-12-11
Start Page: 5360
End Page: 5365
Language: English
DOI: 10.1093/nar/22.24.5360
PROVIDER: scopus
PMCID: PMC332083
PUBMED: 7816626
DOI/URL:
Notes: Export Date: 14 January 2019 -- Article -- CODEN: NARHA C2 -- Source: Scopus
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  1. Stewart H Shuman
    546 Shuman