Evolutionary and dynamic constraints converge on a conserved coupling sector in thermally adapted GH1 β-glucosidases.

BsBgl1A shows the strongest temperature sensitivity among three GH1 β-glucosidases, with non-monotonic dynamic coupling over 300–350 K and pronounced overcoupling at 325 K.

• Why it matters: Thermal adaptation may preserve or reorganize correlated motions, but it is unclear how evolutionary constraints shape dynamic coupling beyond simple structural rigidification.
• What they did: The authors compared BsBgl1A, 9UPT, and LQBG8 using comparative structural analysis, three 1 μs molecular dynamics simulations at 300, 325, and 350 K, neural relational inference of residue-level coupling, and family-level coevolutionary analysis.
• The result: Across all three enzymes, the β1–α5–β1–α7 region repeatedly emerged as a shared structural/dynamic center, with coevolutionary couplings enriched in TIM-barrel regions converging on this sector.