Metal-cation regulation of enzyme dynamics is a key factor influencing the activity of S-adenosyl-L-homocysteine hydrolase from Pseudomonas aeruginosa.

ABSTRACT: S-adenosyl-L-homocysteine hydrolase from Pseudomonas aeruginosa (PaSAHase) coordinates one K⁺ ion and one Zn²⁺ ion in the substrate binding area. The cations affect the enzymatic activity and substrate binding but the molecular mechanisms of their action are unknown. Enzymatic and isothermal titration calorimetry studies demonstrated that the K⁺ ions stimulate the highest activity and strongest ligand binding in comparison to other alkali cations, while the Zn²⁺ ions inhibit the enzyme activity. PaSAHase was crystallized in the presence of adenine nucleosides and K⁺ or Rb⁺ ions. The crystal structures show that the alkali ion is coordinated in close proximity of the purine ring and a ²³Na NMR study showed that the

SUBMITTER: Czyrko J 

PROVIDER: S-EPMC6063907 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature