A hinge migration mechanism unlocks the evolution of green-to-red photoconversion in GFP-like proteins.

Autor:	Kim H; Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA., Zou T; Center for Biological Physics, Department of Physics, Arizona State University, Tempe, AZ 85287, USA., Modi C; Institute for Cellular and Molecular Biology, The University of Texas, Austin, TX 78712, USA., Dörner K; Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA., Grunkemeyer TJ; Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA., Chen L; Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA., Fromme R; Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA., Matz MV; Section of Integrative Biology, The University of Texas, Austin, TX 78712, USA., Ozkan SB; Center for Biological Physics, Department of Physics, Arizona State University, Tempe, AZ 85287, USA. Electronic address: banu.ozkan@asu.edu., Wachter RM; Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA; Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, AZ 85287, USA. Electronic address: rwachter@asu.edu.
Jazyk:	angličtina
Zdroj:	Structure (London, England : 1993) [Structure] 2015 Jan 06; Vol. 23 (1), pp. 34-43.
DOI:	10.1016/j.str.2014.11.011
Abstrakt:	In proteins, functional divergence involves mutations that modify structure and dynamics. Here we provide experimental evidence for an evolutionary mechanism driven solely by long-range dynamic motions without significant backbone adjustments, catalytic group rearrangements, or changes in subunit assembly. Crystallographic structures were determined for several reconstructed ancestral proteins belonging to a GFP class frequently employed in superresolution microscopy. Their chain flexibility was analyzed using molecular dynamics and perturbation response scanning. The green-to-red photoconvertible phenotype appears to have arisen from a common green ancestor by migration of a knob-like anchoring region away from the active site diagonally across the β barrel fold. The allosterically coupled mutational sites provide active site conformational mobility via epistasis. We propose that light-induced chromophore twisting is enhanced in a reverse-protonated subpopulation, activating internal acid-base chemistry and backbone cleavage to enlarge the chromophore. Dynamics-driven hinge migration may represent a more general platform for the evolution of novel enzyme activities. (Copyright © 2015 Elsevier Ltd. All rights reserved.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu