Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1991-1-31
pubmed:abstractText
Substitution of amino acids within the section of Tn21 resolvase that corresponds to a helix-turn-helix structure, with the equivalent residues from Tn3 resolvase, yields proteins that retain the ability to mediate recombination between res sites from Tn21. These proteins had no recombinational activity on res sites from Tn3, even when the complete recognition helix had been exchanged. In this study, the binding of these mutants of Tn21 resolvase to DNA fragments containing res from either Tn21 or Tn3 was analysed by DNase I footprinting and by gel retardation. With DNA containing res from Tn21, the mutants bound to all three of the binding sites for resolvase (I, II, and III) but with a lower affinity than wild-type Tn21 resolvase. No complexes were detected between Tn3 resolvase and Tn21 DNA. With DNA containing res from Tn3, both the mutants and wild-type Tn21 resolvase bound to sites II and III, forming similar complexes to those with Tn3 resolvase: some of the mutants had higher affinities for these two sites on Tn3 DNA than on Tn21 DNA. In contrast, at site I in res from Tn3 (the location of the recombinational cross-over), the derivatives of Tn21 resolvase formed aberrant complexes whose structures differed radically from that with Tn3 resolvase. Alterations in the amino acid sequence of resolvase, within the helix-turn-helix region, therefore modulate the affinity of the protein for its target sequence in the DNA, but the specificity of resolvase for recombination at its cognate res sites is determined by the resultant organization of the DNA-protein complex.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
216
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
645-55
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
DNA binding by mutants of Tn21 resolvase with DNA recognition functions from Tn3 resolvase.
pubmed:affiliation
Department of Biochemistry, University of Bristol, U.K.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't