UniProt functional annotation for P21953



	UniProt functional annotation for P21953

UniProt code: P21953.

Organism: Homo sapiens (Human).

Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.

Function: The branched-chain alpha-keto dehydrogenase complex catalyzes the overall conversion of alpha-keto acids to acyl-CoA and CO(2). It contains multiple copies of three enzymatic components: branched-chain alpha-keto acid decarboxylase (E1), lipoamide acyltransferase (E2) and lipoamide dehydrogenase (E3).

Catalytic activity: Reaction=3-methyl-2-oxobutanoate + [dihydrolipoyllysine-residue (2- methylpropanoyl)transferase]-(R)-N(6)-lipoyl-L-lysine + H(+) = [dihydrolipoyllysine-residue (2-methylpropanoyl)transferase]-(R)- N(6)-(S(8)-2-methylpropanoyldihydrolipoyl)-L-lysine + CO2; Xref=Rhea:RHEA:13457, Rhea:RHEA-COMP:10488, Rhea:RHEA-COMP:10489, ChEBI:CHEBI:11851, ChEBI:CHEBI:15378, ChEBI:CHEBI:16526, ChEBI:CHEBI:83099, ChEBI:CHEBI:83142; EC=1.2.4.4;

Subunit: Heterotetramer of 2 alpha and 2 beta chains.

Subcellular location: Mitochondrion matrix.

Disease: Maple syrup urine disease 1B (MSUD1B) [MIM:248600]: A metabolic disorder due to an enzyme defect in the catabolic pathway of the branched-chain amino acids leucine, isoleucine, and valine. Accumulation of these 3 amino acids and their corresponding keto acids leads to encephalopathy and progressive neurodegeneration. Clinical features include mental and physical retardation, feeding problems, and a maple syrup odor to the urine. The keto acids of the branched-chain amino acids are present in the urine. If untreated, maple syrup urine disease can lead to seizures, coma, and death. The disease is often classified by its pattern of signs and symptoms. The most common and severe form of the disease is the classic type, which becomes apparent soon after birth. Variant forms of the disorder become apparent later in infancy or childhood and are typically milder, but they still involve developmental delay and other medical problems if not treated. {ECO:0000269|PubMed:11509994, ECO:0000269|PubMed:22326532, ECO:0000269|PubMed:8161368}. Note=The disease is caused by variants affecting the gene represented in this entry.

Annotations taken from UniProtKB at the EBI.


Organism:		Homo sapiens (Human).
Taxonomy:		Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.



Function:		The branched-chain alpha-keto dehydrogenase complex catalyzes the overall conversion of alpha-keto acids to acyl-CoA and CO(2). It contains multiple copies of three enzymatic components: branched-chain alpha-keto acid decarboxylase (E1), lipoamide acyltransferase (E2) and lipoamide dehydrogenase (E3).


Catalytic activity:		Reaction=3-methyl-2-oxobutanoate + [dihydrolipoyllysine-residue (2- methylpropanoyl)transferase]-(R)-N(6)-lipoyl-L-lysine + H(+) = [dihydrolipoyllysine-residue (2-methylpropanoyl)transferase]-(R)- N(6)-(S(8)-2-methylpropanoyldihydrolipoyl)-L-lysine + CO2; Xref=Rhea:RHEA:13457, Rhea:RHEA-COMP:10488, Rhea:RHEA-COMP:10489, ChEBI:CHEBI:11851, ChEBI:CHEBI:15378, ChEBI:CHEBI:16526, ChEBI:CHEBI:83099, ChEBI:CHEBI:83142; EC=1.2.4.4;
Subunit:		Heterotetramer of 2 alpha and 2 beta chains.
Subcellular location:		Mitochondrion matrix.
Disease:		Maple syrup urine disease 1B (MSUD1B) [MIM:248600]: A metabolic disorder due to an enzyme defect in the catabolic pathway of the branched-chain amino acids leucine, isoleucine, and valine. Accumulation of these 3 amino acids and their corresponding keto acids leads to encephalopathy and progressive neurodegeneration. Clinical features include mental and physical retardation, feeding problems, and a maple syrup odor to the urine. The keto acids of the branched-chain amino acids are present in the urine. If untreated, maple syrup urine disease can lead to seizures, coma, and death. The disease is often classified by its pattern of signs and symptoms. The most common and severe form of the disease is the classic type, which becomes apparent soon after birth. Variant forms of the disorder become apparent later in infancy or childhood and are typically milder, but they still involve developmental delay and other medical problems if not treated. {ECO:0000269\|PubMed:11509994, ECO:0000269\|PubMed:22326532, ECO:0000269\|PubMed:8161368}. Note=The disease is caused by variants affecting the gene represented in this entry.