Cytosolic fatty-acid binding
IPR000463
Definition
The Fatty Acid-Binding Proteins (FABPs) are a family of proteins that are principally located in the cytosol and are characterised by the ability to bind to hydrophobic ligands, such as fatty acids, retinol, retinoic acid, bile salts and pigments [[cite:PMID:3129018], [cite:PMID:2266967]]. Recently, a number of family members have been identified that are secreted, such as gastrotropin and mammary-derived growth inhibitor. The family is implicated in general lipid metabolism, acting as intracellular transporters of hydrophobic metabolic intermediates and as carriers of lipids between membranes [[cite:PMID:3129018], [cite:PMID:2266967], [cite:PMID:2266965]]. The FABPs exhibit a high degree both of sequence and structural similarity. They are small, 12-18kDa, soluble proteins composed of 110-160 residues. Their crystal structures show them to be 10-stranded anti-parallel β-barrels with a +1,+1 topology, which wrap around an internal cavity to form a ligand binding site [[cite:PMID:2266967], [cite:PMID:2266965]]. Ligand specificity and affinity is governed by the side chains of amino acids that extend into the cavity, especially the polar residue that interacts through hydrogen bonding and electrostatic interactions with the polar head group of the ligand PMID:8422392. An arginine or a glutamine residue is used for binding fatty acids or retinoids, respectively. The anti-parallel β-barrel fold is also exploited by the lipocalins, which function similarly by binding small hydrophobic molecules. Similarity at the sequence level, however, is less obvious, being confined to a single short N-terminal motif.
17 human proteins with this domain
Each is a reviewed human protein in the Seroatlas serome and a potential autoantibody target; this domain groups them into one antibody-relevant category. Every entry links to its own record.
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