Conformational flexibility of His200 enables catalytic activity in the T200H mutant of carbonic anhydrase II.

ABSTRACT: Carbonic anhydrase II (CAII) is one of the most efficient enzymes known, catalyzing the reversible hydration of CO₂ to regulate pH and facilitate CO₂ transport in biological systems. Its exceptional catalytic rate depends on a highly ordered active site composed of a Zn²⁺ ion and a hydrogen-bonded water network that supports substrate binding, proton transfer, and product release. Among the residues maintaining this network, Thr200 plays a crucial role by stabilizing key water molecules. To investigate the structural and functional consequences of perturbing this network, we examined the T200H mutant of CAII using high-pressure cryocooling and X-ray crystallography under CO₂ pressures of 0, 5, and 20 atm. The crystallographic snapshots captured t

SUBMITTER: Lim SW 

PROVIDER: S-EPMC12205326 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature