Cystathionine beta-synthase

Function

Cystathionine β-synthase (CBS) catalyzes the PLP-dependent interconversion of cysteine and homocysteine. In bacterial systems CBS catalyzes the transfer of thiol from cysteine to homocysteine and in mammalian systems from homocysteine to cysteine^[1]..

Disease

CBS deficiency causes homocysteinuria which affects the eye, skeletal system, vascular system and the CNS^[2]. Mutations in Ala114, Ile278, G305 and G307 were found to be involved in homocysteinuria^[3].

Structural highlights

The structure of the complex of CBS with heme, PLP and SAM shows the N-terminal domain which binds the heme cofactor interacting with Cys52 and His65. The catalytic core interacts with the PLP cofactor at Lys119 and a C-terminal regulatory domain.

3D structures of cystathionine β-synthase

Cystathionine β-synthase 3D structures