Reaction mechanism and regulation of cystathionine beta-synthase.
In mammals, cystathionine beta-synthase catalyzes the first step in the transsulfuration pathway which provides an avenue for the conversion of the essential amino acid, methionine, to cysteine. Cystathionine beta-synthase catalyzes a PLP-dependent condensation of serine and homocysteine to cystathionine and is unique in also having a heme cofactor. In this review, recent advances in our understanding of the kinetic mechanism of the yeast and human enzymes as well as pathogenic mutants of the human enzyme and insights into the role of heme in redox sensing are discussed from the perspective of the crystal structure of the catalytic core of the human enzyme.
Banerjee
Ruma
R
Biochemistry Department, University of Nebraska, Lincoln, NE 68588-0664, USA. rbanerjee1@unl.edu
Evande
Ruby
R
Kabil
Omer
O
Ojha
Sunil
S
Taoka
Shin
S
D000494:Allosteric Regulation; D003541:Cystathionine beta-Synthase / Q000737:chemistry* / Q000378:metabolism; D006418:Heme / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D010084:Oxidation-Reduction; D012436:S-Adenosylmethionine / Q000494:pharmacology
D006418:Heme; D012436:S-Adenosylmethionine; D003541:Cystathionine beta-Synthase