Refinement of the structure of recombinant rat intestinal fatty acid-binding apoprotein at 1.2-A resolution.

摘要: 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 1.19 A. final model conventional crystallographic R-factor 16.9% for 34,290 unique reflections [a root mean square (r.m.s.) deviation bond length 0.012 A and r.m.s. 2.368 degrees angles]. Ninety-two residues are present as components protein's 10 anti-parallel beta-strands while 14 part its two short alpha-helices. alpha-helices organized into nearly orthogonal beta-sheets. Particular attention placed in defining solvent structures discretely disordered groups this protein. Two hundred thirty-seven molecules have identified; 24 located within apoI-FABP. includes alternate conformers 228 protein atoms (109 main-chain, 119 side-chain) 63 molecules. We found several aromatic side-chains multiple conformations near, or in, binding site. This observation, along fact that these temperature factor is relatively higher than other residues, suggests they may be involved process noncovalent acid. absence true hydrophobic core I-FABP structural integrity maintained primarily by hydrogen bonding network involving atoms.