Linked Life Data

12668677

Source:http://linkedlifedata.com/resource/pubmed/id/12668677

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
2003-6-2
pubmed:abstractText
The gene for the mismatch-specific uracil glycosylase (MUG) was identified in the Escherichia coli genome as a sequence homolog of the mammalian thymine DNA glycosylase, with activity against uracil in U.G mismatches. Subsequently, 3,N4-ethenocytosine (epsilonC), thymine, 5-hydroxymethyluracil, and 8-(hydroxymethyl)-3,N4-ethenocytosine have been proposed as possible substrates for this enzyme. The evaluation of various DNA adducts as substrates is complicated by the biphasic nature of the kinetics of this enzyme. Our results demonstrate that product release by the enzyme is very slow and hence comparing the "steady-state" parameters of the enzyme for different substrates is of limited use. Consequently, the ability of the enzyme to excise a variety of damage products of purines and pyrimidines was studied under single turnover conditions. Although the enzyme excised both epsilonC and U from DNA, the former adduct was significantly better as a substrate in terms of binding and hydrolysis. Some products of oxidative and alkylation damage are also moderately good substrates for the enzyme, but thymine is a poor substrate. This comparison of different substrates under single turnover conditions provides a rational basis for comparing substrates of MUG and we relate these conclusions to the known crystal structures of the enzyme and its catalytic mechanism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20526-32
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Mismatch uracil glycosylase from Escherichia coli: a general mismatch or a specific DNA glycosylase?
pubmed:affiliation
Imperial College London, Department of Biological Sciences, Sir Alexander Flemming Building, South Kensington, London SW7 2AZ, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't