Linked Life Data

12051845

Source:http://linkedlifedata.com/resource/pubmed/id/12051845

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-6-7
pubmed:abstractText
The SfiI endonuclease is a tetrameric protein with two DNA-binding clefts. It has to bind two copies of its recognition sequence, one at each cleft, before it cleaves DNA. While SfiI binds cooperatively to two cognate sites, it binds only one non-cognate DNA molecule at a time and the resultant complex is precluded from binding cognate DNA at the vacant cleft. To examine the communications between separate binding sites in a protein that synapses two segments of DNA, SfiI was tested with oligonucleotide duplexes containing its recognition sequence but with either R(p) or S(p) phosphorothioate linkages at the scissile bonds. Though SfiI has low activity on the R(p) and none against the S(p) diastereoisomer, it bound these duplexes in the same cooperative manner as oxyester duplexes, though with a reduced affinity for the S(p) derivative. It also formed complexes with one phosphorothioate-duplex and one oxyester-duplex but, when Mg(2+) was added to the hybrid complexes, the phosphorothioate moiety at one DNA-binding cleft prevented the enzyme from cleaving the oxyester duplex at the other cleft. SfiI is thus restrained from catalytic action until it recognises the correct nucleotide sequence at two DNA loci and the correct phosphodiester functions at both loci.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
(c) 2002 Elsevier Science Ltd.
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
318
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
387-94
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Communications between catalytic sites in the protein-DNA synapse by the SfiI endonuclease.
pubmed:affiliation
Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't