Active Sites of O₂-Evolving Chlorite Dismutases Probed by Halides and Hydroxides and New Iron-Ligand Vibrational Correlations.

ABSTRACT: O₂-evolving chlorite dismutases (Clds) fall into two subfamilies, which efficiently convert ClO₂^- to O₂ and Cl^-. The Cld from Dechloromonas aromatica (DaCld) represents the chlorite-decomposing homopentameric enzymes found in perchlorate- and chlorate-respiring bacteria. The Cld from the Gram-negative human pathogen Klebsiella pneumoniae (KpCld) is representative of the second subfamily, comprising homodimeric enzymes having truncated N-termini. Here steric and nonbonding properties of the DaCld and KpCld active sites have been probed via kinetic, thermodynamic, and spectroscopic behaviors of their fluorides, chlorides, and hydroxides. Cooperative binding of Cl^- to KpCld drives formation of a hexacoordinate, high-spin aqua h

SUBMITTER: Geeraerts Z 

PROVIDER: S-EPMC5602553 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature