2ifb | pdb_00002ifb
CRYSTAL STRUCTURE OF RAT INTESTINAL FATTY-ACID-BINDING PROTEIN. REFINEMENT AND ANALYSIS OF THE ESCHERICHIA COLI-DRIVED PROTEIN WITH BOUND PALMITATE
Structural highlights
Function[FABPI_RAT] FABP are thought to play a role in the intracellular transport of long-chain fatty acids and their acyl-CoA esters. FABP2 is probably involved in triglyceride-rich lipoprotein synthesis. Binds saturated long-chain fatty acids with a high affinity, but binds with a lower affinity to unsaturated long-chain fatty acids. FABP2 may also help maintain energy homeostasis by functioning as a lipid sensor (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedRat intestinal fatty-acid-binding protein (I-FABP) is a small (15,124 Mr) cytoplasmic polypeptide that binds long-chain fatty acids in a non-covalent fashion. I-FABP is a member of a family of intracellular binding proteins that are thought to participate in the uptake, transport and/or metabolic targeting of hydrophobic ligands. The crystal structure of Escherichia coli-derived rat I-FABP with a single molecule of bound palmitate has been refined to 2 A resolution using a combination of least-squares methods, energy refinement and molecular dynamics. The combined methods resulted in a model with a crystallographic R-factor of 17.8% (7775 reflections, sigma greater than 2.0), root-mean-square bond length deviation of 0.009 A and root-mean-square bond angle deviation of 2.85 degrees. I-FABP contains ten antiparallel beta-strands organized into two approximately orthogonal, beta-sheets. The hydrocarbon tail of its single C16:0 ligand is present in a well-ordered, distinctively bent conformation. The carboxylate group of the fatty acid is located in the interior of I-FABP and forms a unique "quintet" of electrostatic interactions involving Arg106; Gln 115, and two solvent molecules. The hydrocarbon tail is bent with a slight left-handed helical twist from the carboxylate group to C-16. The bent methylene chain resides in a "cradle" formed by the side-chains of hydrophobic, mainly aromatic, amino acid residues. The refined molecular model of holo-I-FABP suggests several potential locations for entry and exiting of the fatty acid. Crystal structure of rat intestinal fatty-acid-binding protein. Refinement and analysis of the Escherichia coli-derived protein with bound palmitate.,Sacchettini JC, Gordon JI, Banaszak LJ J Mol Biol. 1989 Jul 20;208(2):327-39. PMID:2671390[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||
