1ICM

ESCHERICHIA COLI-DERIVED RAT INTESTINAL FATTY ACID BINDING PROTEIN WITH BOUND MYRISTATE AT 1.5 A RESOLUTION AND I-FABPARG106-->GLN WITH BOUND OLEATE AT 1.74 A RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Observed: 0.159 

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This is version 1.4 of the entry. See complete history


Literature

Escherichia coli-derived rat intestinal fatty acid binding protein with bound myristate at 1.5 A resolution and I-FABPArg106-->Gln with bound oleate at 1.74 A resolution.

Eads, J.Sacchettini, J.C.Kromminga, A.Gordon, J.I.

(1993) J Biol Chem 268: 26375-26385

  • Primary Citation of Related Structures:  
    1ICM, 1ICN

  • PubMed Abstract: 

    Rat intestinal fatty acid binding protein (I-FABP) is a 131-residue protein composed of two short alpha-helices (alpha I and alpha II) and 10 anti-parallel beta-strands organized into two nearly orthogonal beta-sheets. The structure of crystalline I-FABP with bound tetradecanoate (myristate) has been refined to a resolution of 1.5 A and compared to the 1.2 A structure of apo-I-FABP, the 1.9 A structure of I-FABP:hexadecanoate (palmitate) and the 1.75 A structure of I-FABP:9Z-octadecanoate (oleate) to determine how this model fatty acid receptor accommodates changes in the length of its fatty acid ligand. Myristate is located in the interior of the protein. A highly ordered, electrostatic network containing 7 hydrogen (H)-bonds links the OE1 and OE2 atoms of myristate's carboxylate group, the indole nitrogen of Trp82, NH1, and NH2 of Arg106, NE2, and OE1 of Gln115, and 2 interior ordered waters. The hydrocarbon chain of the bound fatty acid is slightly bent. Its convex face lies in a crevice, forming van der Waals contacts with the side chains of several hydrophobic and aromatic residues. Its concave face is exposed to an array of 8 interior ordered waters whose positions are stabilized by H-bond interactions with other waters, H-bond interactions with the side chains of polar/ionizable residues, and van der Waals contacts with the surface of the fatty acid. Addition of 2 or 4 methylenes to myristate produces remarkably little change in the positions of I-FABP's main chain and side chain atoms and interior ordered waters. The principal alterations are in the conformation of a surface opening (portal) connecting external and internal solvent and in the position of the benzene side chain of Phe55. Changes in the conformation of the portal reflect movement of two of its components: the backbone of alpha II and a type I turn (Ala73, Asp74) connecting two beta-strands. The positions of the main chain atoms of Ala73 and Asp74 appear to be determined by their ability to form van der Waals contacts with the omega-terminus of the fatty acid. The side chain of Phe55 appears to function as an adjustable aromatic lid, located over the portal, whose position is dependent on an ability to form van der Waals contacts with a fatty acid's omega-terminus.(ABSTRACT TRUNCATED AT 400 WORDS)


  • Organizational Affiliation

    Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
INTESTINAL FATTY ACID BINDING PROTEIN131Rattus norvegicusMutation(s): 0 
UniProt
Find proteins for P02693 (Rattus norvegicus)
Explore P02693 
Go to UniProtKB:  P02693
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02693
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
MYR
Query on MYR

Download Ideal Coordinates CCD File 
B [auth A]MYRISTIC ACID
C14 H28 O2
TUNFSRHWOTWDNC-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Observed: 0.159 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 36.05α = 90
b = 51.8β = 92
c = 31.48γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
TNTrefinement
X-PLORrefinement
X-PLORphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1994-01-31
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other
  • Version 1.4: 2024-02-07
    Changes: Data collection, Database references, Derived calculations