Active-site protein dynamics and solvent accessibility in native Achromobacter cycloclastes copper nitrite reductase.

ABSTRACT: Microbial nitrite reductases are denitrifying enzymes that are a major component of the global nitrogen cycle. Multiple structures measured from one crystal (MSOX data) of copper nitrite reductase at 240 K, together with molecular-dynamics simulations, have revealed protein dynamics at the type 2 copper site that are significant for its catalytic properties and for the entry and exit of solvent or ligands to and from the active site. Molecular-dynamics simulations were performed using different protonation states of the key catalytic residues (Asp_CAT and His_CAT) involved in the nitrite-reduction mechanism of this enzyme. Taken together, the crystal structures and simulations show that the Asp_CAT protonation state strongly influences the active-site solvent

SUBMITTER: Sen K 

PROVIDER: S-EPMC5571812 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature