Structural role of two histidines in the (6-4) photolyase reaction

• Yamada Daichi

  Department of Frontier Materials, Nagoya Institute of Technology

• Iwata Tatsuya

  Department of Frontier Materials, Nagoya Institute of Technology OptoBioTechnology Research Center, Nagoya Institute of Technology

• Yamamoto Junpei

  Graduate School of Engineering Science, Osaka University

• Hitomi Kenichi

  Department of Integrative Structural and Computational Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute

• Todo Takeshi

  Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University

• Iwai Shigenori

  Graduate School of Engineering Science, Osaka University

• D. Getzoff Elizabeth

  Department of Integrative Structural and Computational Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute

• Kandori Hideki

  Department of Frontier Materials, Nagoya Institute of Technology OptoBioTechnology Research Center, Nagoya Institute of Technology

Abstract

Photolyases (PHRs) are DNA repair enzymes that revert UV-induced photoproducts, either cyclobutane pyrimidine dimers (CPD) or (6-4) photoproducts (PPs), into normal bases to maintain genetic integrity. (6-4) PHR must catalyze not only covalent bond cleavage, but also hydroxyl or amino group transfer, yielding a more complex mechanism than that postulated for CPD PHR. Previous mutation analysis revealed the importance of two histidines in the active center, H354 and H358 for Xenopus (6-4) PHR, whose mutations significantly lowered the enzymatic activity. Based upon highly sensitive FTIR analysis of the repair function, here we report that both H354A and H358A mutants of Xenopus (6-4) PHR still maintain their repair activity, although the efficiency is much lower than that of the wild type. Similar difference FTIR spectra between the wild type and mutant proteins suggest a common mechanism of repair in which (6-4) PP binds to the active center of each mutant, and is released after repair, as occurs in the wild type. Similar FTIR spectra also suggest that a decrease in volume by the H-to-A mutation is possibly compensated by the addition of water molecule(s). Such a modified environment is sufficient for the repair function that is probably controlled by proton-coupled electron transfer between the enzyme and substrate. On the other hand, two histidines must work in a concerted manner in the active center of the wild-type enzyme, which significantly raises the repair efficiency.

Journal

• Biophysics and Physicobiology

  Biophysics and Physicobiology 12 (0), 139-144, 2015

  The Biophysical Society of Japan

Keywords

• DNA repair
• Light-induced difference FTIR spectra
• FAD
• Hydrogen bond

Details

• CRID: 1390001205764196480
• NII Article ID: 130005118260
• DOI: 10.2142/biophysico.12.0_139
• ISSN: 21894779
• Web Site: https://www.jstage.jst.go.jp/article/biophysico/12/0/12_139/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed