Linked Life Data

19921821

Source:http://linkedlifedata.com/resource/pubmed/id/19921821

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
49
pubmed:dateCreated
2009-12-9
pubmed:abstractText
Mutagenic pyrimidine-pyrimidone (6-4) photoproducts are one of the main DNA lesions induced by solar UV radiation. These lesions can be photoreversed by (6-4) photolyases. The originally published repair mechanism involves rearrangement of the lesion into an oxetane intermediate upon binding to the (6-4) photolyase, followed by light-induced electron transfer from the reduced flavin cofactor. In a recent crystallographic study on a (6-4) photoproduct complexed with (6-4) photolyase from Drosophila melanogaster no oxetane was observed, raising the possibility of a non-oxetane repair mechanism. Using quantum-chemical calculations we find that in addition to repair via an oxetane, a direct transfer of the hydroxyl group results in reversal of the radical anion (6-4) photoproduct. In both mechanisms, the transition states have high energies and correspond to avoided crossings of the ground and excited electronic states. To study whether the repair can proceed via these state crossings, the excited-state potential energy curves were computed. The radical excitation energies and accessibility of the nonadiabatic repair path were found to depend on hydrogen bonds and the protonation state of the lesion. On the basis of the energy calculations, a nonadiabatic repair of the excited (6-4) lesion radical anion via hydroxyl transfer is probable. This repair mechanism is in line with the recent structural data on the (6-4) photolyase from D. melanogaster .
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
16
pubmed:volume
131
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17793-9
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Electronic structure of (6-4) DNA photoproduct repair involving a non-oxetane pathway.
pubmed:affiliation
Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany. Tatjana.Domratcheva@mpimf-heidelberg.mpg.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't