Variations in protein-flavin hydrogen bonding in a light, oxygen, voltage domain produce non-Arrhenius kinetics of adduct decay.

ABSTRACT: Light, oxygen, voltage (LOV) domains utilize a conserved blue light-dependent mechanism to control a diverse array of effector domains in biological and engineered proteins. Variations in the kinetics and efficiency of LOV photochemistry fine-tune various aspects of the photic response. Characterization of the kinetics of a key aspect of this photochemical mechanism in EL222, a blue light responsive DNA binding protein from Erythrobacter litoralis HTCC2594, reveals unique non-Arrhenius behavior in the rate of dark-state cleavage of the photochemically generated adduct. Sequence analysis and mutagenesis studies establish that this effect stems from a Gln to Ala mutation unique to EL222 and homologous proteins from marine bacteria. Kinetic and spectroscopic analyses reveal that hydrogen bond

SUBMITTER: Zoltowski BD 

PROVIDER: S-EPMC3381950 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature