%0 Journal Article
%A Arinkin, Vladimir
%A Granzin, Joachim
%A Krauss, Ulrich
%A Jaeger, Karl-Erich
%A Willbold, Dieter
%A Batra-Safferling, Renu
%T Structural determinants underlying the adduct lifetime in the LOV proteins of Pseudomonas putida
%J The FEBS journal
%V 288
%N 16
%@ 1742-4658
%C Oxford [u.a.]
%I Wiley-Blackwell
%M FZJ-2021-01155
%P 4955-4972
%D 2021
%X The primary photochemistry is similar among the flavin-bound sensory domains of light–oxygen–voltage (LOV) photoreceptors, where upon blue-light illumination a covalent adduct is formed on the microseconds time scale between the flavin chromophore and a strictly conserved cysteine residue. In contrast, the adduct-state decay kinetics vary from seconds to days or longer. The molecular basis for this variation among structurally conserved LOV domains is not fully understood. Here, we selected PpSB2-LOV, a fast-cycling (τrec 3.5 min, 20 °C) short LOV protein from Pseudomonas putida that shares 67% sequence identity with a slow-cycling (τrec 2467 min, 20 °C) homologous protein PpSB1-LOV. Based on the crystal structure of the PpSB2-LOV in the dark state reported here, we used a comparative approach, in which we combined structure and sequence information with molecular dynamic (MD) simulations to address the mechanistic basis for the vastly different adduct-state lifetimes in the two homologous proteins. MD simulations pointed toward dynamically distinct structural region, which were subsequently targeted by site-directed mutagenesis of PpSB2-LOV, where we introduced single- and multisite substitutions exchanging them with the corresponding residues from PpSB1-LOV. Collectively, the data presented identify key amino acids on the Aβ-Bβ, Eα-Fα loops, and the Fα helix, such as E27 and I66, that play a decisive role in determining the adduct lifetime. Our results additionally suggest a correlation between the solvent accessibility of the chromophore pocket and adduct-state lifetime. The presented results add to our understanding of LOV signaling and will have important implications in tuning the signaling behavior (on/off kinetics) of LOV-based optogenetic tools.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:33621443
%U <Go to ISI:>//WOS:000628892400001
%R 10.1111/febs.15785
%U https://juser.fz-juelich.de/record/890732