1XCA

APO-CELLULAR RETINOIC ACID BINDING PROTEIN II


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.180 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of apo-cellular retinoic acid-binding protein type II (R111M) suggests a mechanism of ligand entry.

Chen, X.Tordova, M.Gilliland, G.L.Wang, L.Li, Y.Yan, H.Ji, X.

(1998) J.Mol.Biol. 278: 641-653

  • DOI: 10.1006/jmbi.1998.1734

  • PubMed Abstract: 
  • The crystal structure of unliganded mutant R111M of human cellular retinoic acid-binding protein type II (apo-CRABPII (R111M)) has been determined at 2.3 A and refined to a crystallographic R-factor of 0. 18. Although the mutant protein has lower aff ...

    The crystal structure of unliganded mutant R111M of human cellular retinoic acid-binding protein type II (apo-CRABPII (R111M)) has been determined at 2.3 A and refined to a crystallographic R-factor of 0. 18. Although the mutant protein has lower affinity for all-trans-retinoic acid (RA) than the wild-type, it is properly folded, and its conformation is very similar to the wild-type. apo-CRABPII (R111M) crystallizes in space group P1 with two molecules in the unit cell. The two molecules have high structural similarity except that their alpha2 helices differ strikingly. Analyses of the molecular conformation and crystal packing environment suggest that one of the two molecules assumes a conformation compatible with RA entry. Three structural elements encompassing the opening of the binding pocket exhibit large conformational changes, when compared with holo-CRABPII, which include the alpha2 helix and the betaC-betaD and betaE-betaF hairpin loops. The alpha2 helix is unwound at its N terminus, which appears to be essential for the opening of the RA-binding pocket. Three arginine side-chains (29, 59, and 132) are found with their guanidino groups pointing into the RA-binding pocket. A three-step mechanism of RA entry has been proposed, addressing the opening of the RA entrance, the electrostatic potential that directs entry of RA into the binding pocket, and the intramolecular interactions that stabilize the RA.CRABPII complex via locking the three flexible structural elements when RA is bound.


    Related Citations: 
    • Crystal Structures of Cellular Retinoic Acid Binding Proteins I and II in Complex with All-Trans-Retinoic Acid and a Synthetic Retinoid
      Kleywegt, G.J.,Bergfors, T.,Senn, H.,Le Motte, P.,Gsell, B.,Shudo, K.,Jones, T.A.
      (1994) Structure 2: 1241
    • Crystal Structure of Cellular Retinoic Acid Binding Protein I Shows Increased Access to the Binding Cavity due to Formation of an Intermolecular Beta-Sheet
      Thompson, J.R.,Bratt, J.M.,Banaszak, L.J.
      (1995) J.Mol.Biol. 252: 433


    Organizational Affiliation

    ABL-Basic Research Program, National Cancer Institute-Frederick Cancer Research and Development Center, Frederick, MD 21702, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CELLULAR RETINOIC ACID BINDING PROTEIN TYPE II
A, B
137Homo sapiensMutation(s): 1 
Gene Names: CRABP2
Find proteins for P29373 (Homo sapiens)
Go to Gene View: CRABP2
Go to UniProtKB:  P29373
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.180 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 37.580α = 106.41
b = 62.270β = 90.69
c = 35.120γ = 110.64
Software Package:
Software NamePurpose
XENGENdata reduction
X-PLORmodel building
X-PLORrefinement
XENGENdata scaling
X-PLORphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 1996-12-31 
  • Released Date: 1998-07-01 
  • Deposition Author(s): Chen, X., Ji, X.

Revision History 

  • Version 1.0: 1998-07-01
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance