7A6P

Structural determinants underlying the adduct lifetime in a short LOV protein PpSB2-LOV

Summary for 7A6P

• Entry DOI: 10.2210/pdb7a6p/pdb
• Descriptor: Putative Sensory box protein, DI(HYDROXYETHYL)ETHER, FLAVIN MONONUCLEOTIDE, ... (4 entities in total)
• Functional Keywords: lov domain, pas domain, dimerization, signaling blue light photoreceptor, signaling protein
• Biological source: Pseudomonas putida (strain ATCC 47054 / DSM 6125 / NCIMB 11950 / KT2440)
• Total number of polymer chains: 2
• Total formula weight: 39545.87

Authors

Arinkin, V.,Granzin, J.,Batra-Safferling, R. (deposition date: 2020-08-26, release date: 2021-03-10, Last modification date: 2024-01-31)

Primary citation

Arinkin, V.,Granzin, J.,Krauss, U.,Jaeger, K.E.,Willbold, D.,Batra-Safferling, R.
Structural determinants underlying the adduct lifetime in the LOV proteins of Pseudomonas putida.
Febs J., 288:4955-4972, 2021

PubMed Abstract: 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 (τ 3.5 min, 20 °C) short LOV protein from Pseudomonas putida that shares 67% sequence identity with a slow-cycling (τ 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.

PubMed: 33621443
DOI: 10.1111/febs.15785

Experimental method

X-RAY DIFFRACTION (1.93 Å)