Crystal structure of a prokaryotic (6-4) photolyase with an Fe-S cluster and a 6,7-dimethyl-8-ribityllumazine antenna chromophore.
Zhang, F., Scheerer, P., Oberpichler, I., Lamparter, T., Krauss, N.(2013) Proc Natl Acad Sci U S A 110: 7217-7222
- PubMed: 23589886 
- DOI: https://doi.org/10.1073/pnas.1302377110
- Primary Citation of Related Structures:  
4DJA - PubMed Abstract: 
The (6-4) photolyases use blue light to reverse UV-induced (6-4) photoproducts in DNA. This (6-4) photorepair was thought to be restricted to eukaryotes. Here we report a prokaryotic (6-4) photolyase, PhrB from Agrobacterium tumefaciens, and propose that (6-4) photolyases are broadly distributed in prokaryotes. The crystal structure of photolyase related protein B (PhrB) at 1.45 Å resolution suggests a DNA binding mode different from that of the eukaryotic counterparts. A His-His-X-X-Arg motif is located within the proposed DNA lesion contact site of PhrB. This motif is structurally conserved in eukaryotic (6-4) photolyases for which the second His is essential for the (6-4) photolyase function. The PhrB structure contains 6,7-dimethyl-8-ribityllumazine as an antenna chromophore and a [4Fe-4S] cluster bound to the catalytic domain. A significant part of the Fe-S fold strikingly resembles that of the large subunit of eukaryotic and archaeal primases, suggesting that the PhrB-like photolyases branched at the base of the evolution of the cryptochrome/photolyase family. Our study presents a unique prokaryotic (6-4) photolyase and proposes that the prokaryotic (6-4) photolyases are the ancestors of the cryptochrome/photolyase family.
Organizational Affiliation: 
Botanical Institute, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany.