Structural and Functional Analysis of a Prokaryotic (6‐4) Photolyase from the Aquatic Pathogen Vibrio Cholerae†

Abstract

AbstractPhotolyases are flavoproteins, which are able to repair UV‐induced DNA lesions in a light‐dependent manner. According to their substrate, they can be distinguished as CPD‐ and (6‐4) photolyases. While CPD‐photolyases repair the predominantly occurring cyclobutane pyrimidine dimer lesion, (6‐4) photolyases catalyze the repair of the less prominent (6‐4) photoproduct. The subgroup of prokaryotic (6‐4) photolyases/FeS‐BCP is one of the most ancient types of flavoproteins in the ubiquitously occurring photolyase & cryptochrome superfamily (PCSf). In contrast to canonical photolyases, prokaryotic (6‐4) photolyases possess a few particular characteristics, including a lumazine derivative as antenna chromophore besides the catalytically essential flavin adenine dinucleotide as well as an elongated linker region between the N‐terminal α/β‐domain and the C‐terminal all‐α‐helical domain. Furthermore, they can harbor an additional short subdomain, located at the C‐terminus, with a binding site for a [4Fe‐4S] cluster. So far, two crystal structures of prokaryotic (6‐4) photolyases have been reported. Within this study, we present the high‐resolution structure of the prokaryotic (6‐4) photolyase from Vibrio cholerae and its spectroscopic characterization in terms of in vitro photoreduction and DNA‐repair activity.