Structure of a LOV protein in apo-state and implications for construction of LOV-based optical tools.

ABSTRACT: Unique features of Light-Oxygen-Voltage (LOV) proteins like relatively small size (~12-19?kDa), inherent modularity, highly-tunable photocycle and oxygen-independent fluorescence have lately been exploited for the generation of optical tools. Structures of LOV domains reported so far contain a flavin chromophore per protein molecule. Here we report two new findings on the short LOV protein W619_1-LOV from Pseudomonas putida. First, the apo-state crystal structure of W619_1-LOV at 2.5?Å resolution reveals conformational rearrangements in the secondary structure elements lining the chromophore pocket including elongation of the F? helix, shortening of the E?-F? loop and partial unfolding of the E? helix. Second, the apo W619_1-LOV protein binds both natural and structurally modified flavin chromophores. Remarkably different photophysical and photochemical properties of W619_1-LOV bound to 7-methyl-8-chloro-riboflavin (8-Cl-RF) and lumichrome imply application of these variants as novel optical tools as they offer advantages such as no adduct state formation, and a broader choice of wavelengths for in vitro studies.

SUBMITTER: Arinkin V 

PROVIDER: S-EPMC5314338 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature