| Primary Identifier | IPR003016 | Type | Binding_site |
| Short Name | 2-oxoA_DH_lipoyl-BS |
| description | The 2-oxo acid dehydrogenase multienzyme complexes []from bacterial andeukaryotic sources catalyze the oxidative decarboxylation of 2-oxo acids tothe corresponding acyl-CoA. These include: Pyruvate dehydrogenase complex (PDC). 2-oxoglutarate dehydrogenase complex (OGDC). Branched-chain 2-oxo acid dehydrogenase complex (BCOADC). These three complexes share a common architecture: they are composed ofmultiple copies of three component enzymes - E1, E2 and E3. E1 is a thiaminepyrophosphate-dependent 2-oxo acid dehydrogenase, E2 a dihydrolipamideacyltransferase, and E3 an FAD-containing dihydrolipamide dehydrogenase. E2 acyltransferases have an essential cofactor, lipoic acid, which iscovalently bound via a amide linkage to a lysine group. The E2 components ofOGCD and BCOACD bind a single lipoyl group, while those of PDC bind either one(in yeast and in Bacillus), two (in mammals), or three (in Azotobacter and inEscherichia coli) lipoyl groups []. In addition to the E2 components of the three enzymatic complexes describedabove, a lipoic acid cofactor is also found in the following proteins: H-protein of the glycine cleavage system (GCS) []. GCS is a multienzymecomplex of four protein components, which catalyzes the degradation ofglycine. H protein shuttles the methylamine group of glycine from the Pprotein to the T protein. H-protein from either prokaryotes or eukaryotesbinds a single lipoic group. Mammalian and yeast pyruvate dehydrogenase complexes differ from that ofother sources, in that they contain, in small amounts, a protein of unknownfunction - designated protein X or component X. Its sequence is closelyrelated to that of E2 subunits and seems to bind a lipoic group []. Fast migrating protein (FMP) (gene acoC) from Ralstonia eutropha (Alcaligenes eutrophus) [].This protein is most probably a dihydrolipamide acyltransferase involved inacetoin metabolism. This signature contains the lipoyl-binding lysine residue. The domain surronding this site is evolutionary related to that around the biotin-binding lysine residue of biotin requiring enzymes. |
