Functional role of an unusual tyrosine residue in the electron transfer chain of a prokaryotic (6–4) photolyase

Abstract

FAD photoreduction mechanism by different aromatic residues in a phylogenetically ancient photolyase.

What accounts for the different functions in photolyases and cryptochromes: a computational study of proton transfers to FAD

“…32 Computational chemistry methods provide a consistent and comparatively cheap approach to investigate the effect of differences at a molecular level between the FAD pockets from CRYI, PL-WT and mutants. In our previous study, 28 we computed rate constants for both ET [29][30][31] and PT 28 processes in CRYI in agreement with the experimental results. The aim of the current study is to resolve the mechanism and energetics of the PT processes taking place in PL-WT and PL-N378D, and compare to those in CRYI (see Fig.…”

Photolyases and Cryptochromes in UV‐resistant Bacteria from High‐altitude Andean Lakes

“…Furthermore, Tyr residues are also involved in ET in other photolyases: for example in the CPD class I photolyase from Anacystis nidulans , and in Methanosarcina mazei CPD class II photolyase, a Tyr residue is required for full photoreduction. In the Xenopus laevis (6–4) photolyase, the involvement of a Tyr residue in photoreduction was shown by electron paramagnetic resonance (Weber 2002, Holub 2017). But in all cases studied, the tyrosine is coupled to tryptophans.…”

How Mg2+stimulates DNA repair in prokaryotic (6-4) photolyases

“…Three starting structures have been defined considering the three possible protonation states of H366: Nεs protonation, Nδ protonation or positively charged and double protonated histidine. The force field parameters for DMRL and the iron sulfur cluster have been described earlier [11]. The FADH-parameters were taken from the AMBER force field [31, 32] and the charges were determined using the RESP approach [33].…”

“…(v) The photoreduction chain is composed of two Trp and one central Tyr in FeS-BCP proteins. This function was overtaken by an unrelated Trp triad in other photolyases and cryptochromes [11] (vi) The repair activity for (6-4) photoproducts of short single stranded oligonucleotides by PhrB and CryB was increased about thousandfold by the addition of Mg 2+ or other divalent cations [12]. Such an effect is absent from photolyases of other groups.…”