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Photolyase: Dynamics and Mechanisms of Repair of Sun‐Induced DNA Damage
Author(s) -
Zhang Meng,
Wang Lijuan,
Zhong Dongping
Publication year - 2017
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.12695
Subject(s) - photolyase , dynamics (music) , dna damage , dna repair , dna , biophysics , biology , microbiology and biotechnology , chemistry , computational biology , genetics , physics , acoustics
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.