Key Residues for Catalytic Function and Metal Coordination in a Carotenoid Cleavage Dioxygenase.

ABSTRACT: Carotenoid cleavage dioxygenases (CCDs) are non-heme iron-containing enzymes found in all domains of life that generate biologically important apocarotenoids. Prior studies have revealed a critical role for a conserved 4-His motif in forming the CCD iron center. By contrast, the roles of other active site residues in catalytic function, including maintenance of the stringent regio- and stereo-selective cleavage activity, typically exhibited by these enzymes have not been thoroughly investigated. Here, we examined the functional and structural importance of active site residues in an apocarotenoid-cleaving oxygenase (ACO) from Synechocystis Most active site substitutions variably lowered maximal catalytic activity without markedly affecting the Km value for the all-trans-8'-apocarotenol sub

SUBMITTER: Sui X 

PROVIDER: S-EPMC5016679 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature