title: Photolyase: Dynamics and Mechanisms of Repair of Sun-Induced DNA Damage.
abstract: Photolyase, a photomachine discovered half a century ago for repair of sun-induced DNA damage of cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone photoproducts (6-4PPs), has been characterized extensively in biochemistry (function), structure and dynamics since 1980s. The molecular mechanism and repair photocycle have been revealed at the most fundamental level. Using femtosecond spectroscopy, we have mapped out the entire dynamical evolution and determined all actual timescales of the catalytic processes. Here, we review our recent efforts in studies of the dynamics of DNA repair by photolyases. The repair of CPDs in three life kingdoms includes seven electron transfer (ET) reactions among 10 elementary steps through initial bifurcating ET pathways, a direct tunneling route and a two-step hopping path both through an intervening adenine from the cofactor to CPD, with a conserved folded structure at the active site. The repair of 6-4PPs is challenging and requires similar ET reactions and a new cyclic proton transfer with a conserved histidine residue at the active site of (6-4) photolyases. Finally, we also summarize our efforts on multiple intraprotein ET of photolyases in different redox states and such mechanistic studies are critical to the functional mechanism of homologous cryptochromes of blue-light photoreceptors.
authors.affiliation: Department of Physics, The Ohio State University, Columbus, OH.|Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH.|Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, OH.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Physics, The Ohio State University, Columbus, OH.|Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH.|Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, OH.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Physics, The Ohio State University, Columbus, OH.|Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH.|Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, OH.
authors.forename: Dongping
authors.initials: D
authors.lastname: Zhong
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage / Q000528:radiation effects*; D004260:DNA Repair; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000737:chemistry / Q000378:metabolism*; D004579:Electron Transport; D004735:Energy Transfer; D010084:Oxidation-Reduction; D011740:Pyrimidine Dimers / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment; D013472:Sunlight
chemical_list: D011740:Pyrimidine Dimers; D004247:DNA; C098727:pyrimidine(6-4)pyrimidone photolyase; D004255:Deoxyribodipyrimidine Photo-Lyase