Cystathionine Beta Synthase

Cystathionine Beta Synthase

Identifiers Symbols CBS; HIP4 External IDs OMIM: 613381 MGI: 88285 HomoloGene: 37258 GeneCards: CBS Gene EC number 4.2.1.22

Gene Ontology
Molecular function cystathionine beta-synthase activity
protein binding
enzyme binding
heme binding
pyridoxal phosphate binding
ubiquitin protein ligase binding
protein homodimerization activity
metal ion binding
modified amino acid binding
Cellular component nucleus
nucleolus
cytosol
intracellular membrane-bounded organelle
Biological process sulfur amino acid metabolic process
endochondral ossification
blood vessel remodeling
cysteine biosynthetic process from serine
L-serine metabolic process
L-serine catabolic process
superoxide metabolic process
cysteine biosynthetic process via cystathionine
transsulfuration
L-cysteine catabolic process
cerebellum morphogenesis
regulation of cGMP metabolic process
cellular nitrogen compound metabolic process
homocysteine catabolic process
regulation of JUN kinase activity
small molecule metabolic process
homocysteine metabolic process
regulation of blood vessel size
response to folic acid
maternal process involved in female pregnancy
cartilage development involved in endochondral bone morphogenesis
hydrogen sulfide biosynthetic process
Sources: Amigo / QuickGO
Orthologs Species Human Mouse Entrez 875 12411 Ensembl ENSG00000160200 ENSMUSG00000024039 UniProt P35520 Q91WT9 RefSeq (mRNA) NM_000071.2 NM_001271353.1 RefSeq (protein) NP_000062.1 NP_001258282.1 Location (UCSC) Chr 21:
44.47 – 44.5 Mb Chr 17:
31.61 – 31.64 Mb PubMed search

Cystathionine-β-synthase, also known as CBS, is an enzyme (EC 4.2.1.22) that in humans is encoded by the CBS gene. It catalyzes the first step of the transsulfuration pathway, from homocysteine to cystathionine:

L-serine + L-homocysteine L-cystathionine + H2O

CBS uses the cofactor pyridoxal-phosphate (PLP) and can be allosterically regulated by effectors such as the ubiquitous cofactor S-adenosyl-L-methionine (adoMet). This enzyme belongs to the family of lyases, to be specific, the hydro-lyases, which cleave carbon-oxygen bonds.

CBS is a multidomain enzyme composed of an N-terminal enzymatic domain and two CBS domains. The CBS gene is the most common locus for mutations associated with homocystinuria.

Read more about Cystathionine Beta Synthase:  Nomenclature, Structure, Enzymatic Activity, Regulation, Human Disease, Bioengineering