A Hinge Migration Mechanism Unlocks the Evolution of Green-to-Red Photoconversion in GFP-like Proteins

Journal Article · Thu Jan 01 00:00:00 EST 2015 · Structure

DOI:https://doi.org/10.1016/j.str.2014.11.011· OSTI ID:1242549

Kim, Hanseong; Zou, Taisong; Modi, Chintan; Dörner, Katerina; Grunkemeyer, Timothy J.; Chen, Liqing; Fromme, Raimund; Matz, Mikhail V.; Ozkan, S. Banu; Wachter, Rebekka M.

In proteins, functional divergence involves mutations that modify structure and dynamics. In this paper, 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. Finally, dynamics-driven hinge migration may represent a more general platform for the evolution of novel enzyme activities.

• Research Organization: Arizona State Univ., Tempe, AZ (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: AC02-05CH11231; AC02-06CH11357
• OSTI ID: 1242549
• Alternate ID(s): OSTI ID: 1233914; OSTI ID: 1344510
• Journal Information: Structure, Journal Name: Structure Vol. 23 Journal Issue: 1; ISSN 0969-2126
• Publisher: Elsevier
• Country of Publication: United Kingdom
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
green fluorescent protein
red fluorescent protein
superresolution microscopy
Kaede
photoconversion
photochromism
ancestral gene reconstruction
molecular evolution
protein evolution
protein dynamics
chain flexibility
catalytic base activation
reverse protonation of ionic bonds
principle of kinetic equivalence
allosteric communication