Glycine dehydrogenase (decarboxylating)

Glycine decarboxylase also known as glycine cleavage system P protein or glycine dehydrogenase is an enzyme that in humans is encoded by the GLDC gene.^[5][6][7]

GLDC
Identifiers
Aliases	GLDC, GCE, GCSP, HYGN1, Glycine dehydrogenase, glycine decarboxylase
External IDs	OMIM: 238300; MGI: 1341155; HomoloGene: 141; GeneCards: GLDC; OMA:GLDC - orthologs
Gene location (Human) Chr. Chromosome 9 (human)[1] Band 9p24.1 Start 6,532,467 bp[1] End 6,645,729 bp[1]
Gene location (Mouse) Chr. Chromosome 19 (mouse)[2] Band 19 C1|19 24.87 cM Start 30,075,847 bp[2] End 30,152,829 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in right lobe of liver kidney tubule gonad human kidney ventricular zone sural nerve placenta metanephric glomerulus testicle embryo Top expressed in otic placode otic vesicle yolk sac morula primitive streak morula epiblast left lobe of liver right kidney ciliary body More reference expression data BioGPS More reference expression data
Gene ontology Molecular function lyase activity electron transfer activity oxidoreductase activity catalytic activity pyridoxal phosphate binding protein dimerization activity glycine binding glycine dehydrogenase (decarboxylating) activity protein homodimerization activity pyridoxal binding enzyme binding Cellular component mitochondrial matrix plasma membrane nucleus glycine cleavage complex mitochondrion Biological process cellular amino acid metabolic process glycine metabolic process glycine decarboxylation via glycine cleavage system glycine catabolic process response to methylamine response to lipoic acid cellular response to leukemia inhibitory factor electron transport chain Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 2731 104174 Ensembl ENSG00000178445 ENSMUSG00000024827 UniProt P23378 Q91W43 RefSeq (mRNA) NM_000170 NM_138595 RefSeq (protein) NP_000161 NP_613061 Location (UCSC) Chr 9: 6.53 – 6.65 Mb Chr 19: 30.08 – 30.15 Mb PubMed search [3] [4]
Wikidata
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glycine decarboxylase
Identifiers
EC no.	1.4.4.2
CAS no.	37259-67-9
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Reaction

Glycine decarboxylase (EC 1.4.4.2) is an enzyme that catalyzes the following chemical reaction:

glycine + H-protein-lipoyllysine ${\displaystyle \rightleftharpoons }$ H-protein-S-aminomethyldihydrolipoyllysine + CO₂

Thus, the two substrates of this enzyme are glycine and H-protein-lipoyllysine, whereas its two products are H-protein-S-aminomethyldihydrolipoyllysine and CO₂.^[8]

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH2 group of donors with a disulfide as acceptor. This enzyme participates in glycine, serine and threonine metabolism. It employs one cofactor, pyridoxal phosphate.

Function

Glycine decarboxylase is the P-protein of the glycine cleavage system in eukaryotes. The glycine cleavage system catalyzes the degradation of glycine. The P protein binds the alpha-amino group of glycine through its pyridoxal phosphate cofactor. Carbon dioxide is released and the remaining methylamine moiety is then transferred to the lipoamide cofactor of the H protein.

Degradation of glycine is brought about by the glycine cleavage system, which is composed of four mitochondrial protein components: P protein (a pyridoxal phosphate-dependent glycine decarboxylase), H protein (a lipoic acid-containing protein), T protein (a tetrahydrofolate-requiring enzyme), and L protein (a lipoamide dehydrogenase).^[7]

Clinical significance

Glycine encephalopathy is due to defects in GLDC or AMT of the glycine cleavage system.^[7]