Cross-talk between the catalytic core and the regulatory domain in cystathionine β-synthase: study by differential covalent labeling and computational modeling.

ABSTRACT: Cystathionine β-synthase (CBS) is a modular enzyme which catalyzes condensation of serine with homocysteine. Cross-talk between the catalytic core and the C-terminal regulatory domain modulates the enzyme activity. The regulatory domain imposes an autoinhibition action that is alleviated by S-adenosyl-l-methionine (AdoMet) binding, by deletion of the C-terminal regulatory module, or by thermal activation. The atomic mechanisms of the CBS allostery have not yet been sufficiently explained. Using pulse proteolysis in urea gradient and proteolytic kinetics with thermolysin under native conditions, we demonstrated that autoinhibition is associated with changes in conformational stability and with sterical hindrance of the catalytic core. To determine the contact area between the catalytic core

SUBMITTER: Hnizda A 

PROVIDER: S-EPMC3146298 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature