Linked Life Data

20227927

Source:http://linkedlifedata.com/resource/pubmed/id/20227927

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2010-4-26
pubmed:abstractText
Light-induced activation of class II cyclobutane pyrimidine dimer (CPD) photolyases of Arabidopsis thaliana and Oryza sativa has been examined by UV/Vis and pulsed Davies-type electron-nuclear double resonance (ENDOR) spectroscopy, and the results compared with structure-known class I enzymes, CPD photolyase and (6-4) photolyase. By ENDOR spectroscopy, the local environment of the flavin adenine dinucleotide (FAD) cofactor is probed by virtue of proton hyperfine couplings that report on the electron-spin density at the positions of magnetic nuclei. Despite the amino-acid sequence dissimilarity as compared to class I enzymes, the results indicate similar binding motifs for FAD in the class II photolyases. Furthermore, the photoreduction kinetics starting from the FAD cofactor in the fully oxidized redox state, FAD(ox), have been probed by UV/Vis spectroscopy. In Escherichia coli (class I) CPD photolyase, light-induced generation of FADH from FAD(ox), and subsequently FADH(-) from FADH, proceeds in a step-wise fashion via a chain of tryptophan residues. These tryptophans are well conserved among the sequences and within all known structures of class I photolyases, but completely lacking from the equivalent positions of class II photolyase sequences. Nevertheless, class II photolyases show photoreduction kinetics similar to those of the class I enzymes. We propose that a different, but also effective, electron-transfer cascade is conserved among the class II photolyases. The existence of such electron transfer pathways is supported by the observation that the catalytically active fully reduced flavin state obtained by photoreduction is maintained even under oxidative conditions in all three classes of enzymes studied in this contribution.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1568-7856
pubmed:author
pubmed:copyrightInfo
(c) 2010 Elsevier B.V. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
4
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
495-505
pubmed:meshHeading
pubmed-meshheading:20227927-Amino Acid Sequence, pubmed-meshheading:20227927-Animals, pubmed-meshheading:20227927-Arabidopsis, pubmed-meshheading:20227927-Arabidopsis Proteins, pubmed-meshheading:20227927-Coenzymes, pubmed-meshheading:20227927-Deoxyribodipyrimidine Photo-Lyase, pubmed-meshheading:20227927-Electron Spin Resonance Spectroscopy, pubmed-meshheading:20227927-Electron Transport, pubmed-meshheading:20227927-Enzyme Activation, pubmed-meshheading:20227927-Flavin-Adenine Dinucleotide, pubmed-meshheading:20227927-Free Radicals, pubmed-meshheading:20227927-Light, pubmed-meshheading:20227927-Models, Molecular, pubmed-meshheading:20227927-Molecular Sequence Data, pubmed-meshheading:20227927-Oryza sativa, pubmed-meshheading:20227927-Photochemical Processes, pubmed-meshheading:20227927-Protein Conformation, pubmed-meshheading:20227927-Spectrophotometry, Ultraviolet, pubmed-meshheading:20227927-Xenopus laevis
pubmed:year
2010
pubmed:articleTitle
Light-induced activation of class II cyclobutane pyrimidine dimer photolyases.
pubmed:affiliation
Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural