title: A quantum chemical perspective on (6-4) photolesion repair by photolyases.
abstract: (6-4)-Photolyases are fascinating enzymes which repair (6-4)-DNA photolesions utilizing light themselves. It is well known that upon initial photo-excitation of an antenna pigment an electron is transferred from an adjacent FADH(-) cofactor to the photolesion initiating repair, i.e. restoration of the original undamaged DNA bases. Concerning the molecular details of this amazing repair mechanism, the early steps of energy transfer and catalytic electron generation are well understood, the terminal repair mechanism, however, is still a matter of ongoing debate. In this perspective article, recent results of quantum chemical investigations are presented, and their meaning for the repair mechanism under natural conditions is outlined. Consequences of natural light conditions, temperature and thermal equilibration are highlighted when issues like the initial protonation state of the relevant histidines and the lesion, or the direction of electron transfer are discussed.
authors.affiliation: Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 368, 69120 Heidelberg, Germany. dreuw@uni-heidelberg.de shirin.faraji@uni-heidelberg.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Dreuw
authors.forename: Shirin
authors.initials: S
authors.lastname: Faraji
mesh_terms: D000818:Animals; D055162:Biocatalysis; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004260:DNA Repair; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000737:chemistry* / Q000378:metabolism; D004330:Drosophila / Q000201:enzymology; D004579:Electron Transport; D004583:Electrons; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry; D011789:Quantum Theory; D014466:Ultraviolet Rays
chemical_list: D005182:Flavin-Adenine Dinucleotide; D004247:DNA; D004255:Deoxyribodipyrimidine Photo-Lyase