4dxp
Crystal Structure of a reconstructed Kaede-type Red Fluorescent Protein, LEA X121Crystal Structure of a reconstructed Kaede-type Red Fluorescent Protein, LEA X121
Structural highlights
Publication Abstract from PubMedIn 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 beta 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. A hinge migration mechanism unlocks the evolution of green-to-red photoconversion in GFP-like proteins.,Kim H, Zou T, Modi C, Dorner K, Grunkemeyer TJ, Chen L, Fromme R, Matz MV, Ozkan SB, Wachter RM Structure. 2015 Jan 6;23(1):34-43. doi: 10.1016/j.str.2014.11.011. PMID:25565105[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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