Linked Life Data

9651316

Source:http://linkedlifedata.com/resource/pubmed/id/9651316

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
1998-8-6
pubmed:abstractText
All DNA methyltransferases (MTases) have similar catalytic domains containing nine blocks of conserved amino acid residues. We have investigated by site-directed mutagenesis the function of 17 conserved residues in the EcoRV alpha-adenine-N6-DNA methyltransferase. The structure of this class of MTases has been predicted recently. The variants were characterized with respect to their catalytic activities and their abilities to bind to DNA and the S-adenosylmethionine (AdoMet) cofactor. Amino acids located in motifs X, I, and II are shown to be involved in AdoMet binding (Lys16, Glu37, Phe39, and Asp58). Some of the mutants defective in AdoMet binding are also impaired in DNA binding, suggesting allosteric interactions between the AdoMet and DNA binding site. Asp78 (motif III), which was supposed to form a hydrogen bond to the AdoMet on the basis of the structure predictions, turned out not to be important for AdoMet binding, suggesting that motif III has not been identified correctly. R128A and N130A, having mutations in the putative DNA binding domain, are unable to bind to DNA. Residues located in motifs IV, V, VI, and VIII are involved in catalysis (Asp193, Tyr196, Asp211, Ser229, Trp231, and Tyr258), some of them presumably in binding the flipped target base, because mutations at these residues fail to significantly interfere with DNA and AdoMet binding but strongly reduce catalysis. Our results are in substantial agreement with the structure prediction for EcoRV alpha-adenine-N6-methyltransferase and x-ray structures of other MTases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17333-42
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Functional roles of conserved amino acid residues in DNA methyltransferases investigated by site-directed mutagenesis of the EcoRV adenine-N6-methyltransferase.
pubmed:affiliation
Institut für Biochemie, Fachbereich Biologie, Justus-Liebig-Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't