Structural basis for specificity and promiscuity in a carrier protein/enzyme system from the sulfur cycle.

ABSTRACT: The bacterial Sox (sulfur oxidation) pathway is an important route for the oxidation of inorganic sulfur compounds. Intermediates in the Sox pathway are covalently attached to the heterodimeric carrier protein SoxYZ through conjugation to a cysteine on a protein swinging arm. We have investigated how the carrier protein shuttles intermediates between the enzymes of the Sox pathway using the interaction between SoxYZ and the enzyme SoxB as our model. The carrier protein and enzyme interact only weakly, but we have trapped their complex by using a "suicide enzyme" strategy in which an engineered cysteine in the SoxB active site forms a disulfide bond with the incoming carrier arm cysteine. The structure of this trapped complex, together with calorimetric data, identifies sites of protein-pro

SUBMITTER: Grabarczyk DB 

PROVIDER: S-EPMC4702959 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature