1ifc
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REFINEMENT OF THE STRUCTURE OF RECOMBINANT RAT INTESTINAL FATTY ACID-BINDING APOPROTEIN AT 1.2 ANGSTROMS RESOLUTION
OverviewOverview
The three-dimensional structure of the 131-residue rat intestinal fatty, acid-binding protein, without bound ligand (apoI-FABP), has been refined, with x-ray diffraction data to a nominal resolution of 1.19 A. The final, model has a conventional crystallographic R-factor of 16.9% for 34,290, unique reflections [a root mean square (r.m.s.) deviation for bond length, of 0.012 A and a r.m.s. deviation of 2.368 degrees for bond angles]., Ninety-two residues are present as components of the protein's 10, anti-parallel beta-strands while 14 residues are part of its two short, alpha-helices. The beta-strands and alpha-helices are organized into two, nearly orthogonal beta-sheets. Particular attention has been placed in, defining solvent structure and the structures of discretely disordered, groups in this protein. Two hundred thirty-seven solvent molecules have, been identified; 24 are located within apoI-FABP. The refined model, includes alternate conformers for 228 protein atoms (109 main-chain, 119, side-chain) and 63 solvent molecules. We have found several aromatic, side-chains with multiple conformations located near, or in, the protein's, ligand binding site. This observation, along with the fact that these, side-chains have a temperature factor that is relatively higher than that, of other aromatic residues, suggests that they may be involved in the, process of noncovalent binding of fatty acid. The absence of a true, hydrophobic core in I-FABP suggests that its structural integrity may be, maintained primarily by a hydrogen bonding network involving protein and, solvent atoms.
About this StructureAbout this Structure
1IFC is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
ReferenceReference
Refinement of the structure of recombinant rat intestinal fatty acid-binding apoprotein at 1.2-A resolution., Scapin G, Gordon JI, Sacchettini JC, J Biol Chem. 1992 Feb 25;267(6):4253-69. PMID:1740465
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