PROSITE documentation PDOC00686Acyl-CoA-binding (ACB) domain signature and profile
Acyl-CoA-binding protein (ACBP) is a small (10 Kd) protein that binds medium- and long-chain acyl-CoA esters with very high affinity and may function as an intracellular carrier of acyl-CoA esters [1]. ACBP is also known as diazepam binding inhibitor (DBI) or endozepine (EP) because of its ability to displace diazepam from the benzodiazepine (BZD) recognition site located on the GABA type A receptor. It is therefore possible that this protein also acts as a neuropeptide to modulate the action of the GABA receptor [2].
ACBP is a highly conserved protein of about 90 residues that is found in all four eukaryotic kingdoms, Animalia, Plantae, Fungi and Protista, and in some eubacterial species [3].
Although ACBP occurs as a completely independent protein, intact ACB domains have been identified in a number of large, multifunctional proteins in a variety of eukaryotic species. These include large membrane-associated proteins with N-terminal ACB domains, multifunctional enzymes with both ACB and peroxisomal enoyl-CoA Delta(3), Delta(2)-enoyl-CoA isomerase domains, and proteins with both an ACB domain and ankyrin repeats (see <PDOC50088>) [3].
The ACB domain consists of four α-helices arranged in a bowl shape with a highly exposed acyl-CoA-binding site (see <PDB:1HBK>). The ligand is bound through specific interactions with residues on the protein, most notably several conserved positive charges that interact with the phosphate group on the adenosine-3'phosphate moiety, and the acyl chain is sandwiched between the hydrophobic surfaces of CoA and the protein [4].
ACBP belongs to a family that also includes:
- Endozepine-like peptide (ELP) (gene DBIL5) from mouse [5]. ELP is a testis- specific ACBP homolog that may be involved in the energy metabolism of the mature sperm.
- MA-DBI, a transmembrane protein of unknown function which has been found in mammals. MA-DBI contains a N-terminal ACB domain.
- DRS-1 [6], a human protein of unknown function that contains a N-terminal ACB domain and a C-terminal enoyl-CoA isomerase/hydratase domain.
As a signature pattern we selected the region that corresponds to residue 19 to 37 in mammalian ACBP. We also developed a profile which covers the entire ACB domain.
Last update:July 2006 / Text revised; profile added.
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PROSITE methods (with tools and information) covered by this documentation:
| 1 | Authors | Rose T.M. Schultz E.R. Todaro G.J. |
| Title | Molecular cloning of the gene for the yeast homolog (ACB) of diazepam binding inhibitor/endozepine/acyl-CoA-binding protein. | |
| Source | Proc. Natl. Acad. Sci. U.S.A. 89:11287-11291(1992). | |
| PubMed ID | 1454809 |
| 2 | Authors | Costa E. Guidotti A. |
| Title | Diazepam binding inhibitor (DBI): a peptide with multiple biological actions. | |
| Source | Life Sci. 49:325-344(1991). | |
| PubMed ID | 1649940 |
| 3 | Authors | Burton M. Rose T.M. Faergeman N.J. Knudsen J. |
| Title | Evolution of the acyl-CoA binding protein (ACBP). | |
| Source | Biochem. J. 392:299-307(2005). | |
| PubMed ID | 16018771 | |
| DOI | 10.1042/BJ20050664 |
| 4 | Authors | van Aalten D.M.F. Milne K.G. Zou J.Y. Kleywegt G.J. Bergfors T. Ferguson M.A.J. Knudsen J. Jones T.A. |
| Title | Binding site differences revealed by crystal structures of Plasmodium falciparum and bovine acyl-CoA binding protein. | |
| Source | J. Mol. Biol. 309:181-192(2001). | |
| PubMed ID | 11491287 | |
| DOI | 10.1006/jmbi.2001.4749 |
| 5 | Authors | Pusch W. Balvers M. Hunt N. Ivell R. |
| Title | A novel endozepine-like peptide (ELP) is exclusively expressed in male germ cells. | |
| Source | Mol. Cell. Endocrinol. 122:69-80(1996). | |
| PubMed ID | 8898349 |
| 6 | Authors | Suk K. Kim Y.-H. Hwang D.-Y. Ihm S.H. Yoo H.J. Lee M.S. |
| Title | Molecular cloning and expression of a novel human cDNA related to the diazepam binding inhibitor. | |
| Source | Biochim. Biophys. Acta 1454:126-131(1999). | |
| PubMed ID | 10354522 |
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