1QAB

The structure of human retinol binding protein with its carrier protein transthyretin reveals interaction with the carboxy terminus of RBP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.2 Å
  • R-Value Free: 0.403 
  • R-Value Work: 0.278 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The structure of human retinol-binding protein (RBP) with its carrier protein transthyretin reveals an interaction with the carboxy terminus of RBP.

Naylor, H.M.Newcomer, M.E.

(1999) Biochemistry 38: 2647-2653

  • DOI: 10.1021/bi982291i
  • Also Cited By: 3BSZ

  • PubMed Abstract: 
  • Whether ultimately utilized as retinoic acid, retinal, or retinol, vitamin A is transported to the target cells as all-trans-retinol bound to retinol-binding protein (RBP). Circulating in the plasma, RBP itself is bound to transthyretin (TTR, previou ...

    Whether ultimately utilized as retinoic acid, retinal, or retinol, vitamin A is transported to the target cells as all-trans-retinol bound to retinol-binding protein (RBP). Circulating in the plasma, RBP itself is bound to transthyretin (TTR, previously referred to as thyroxine-binding prealbumin). In vitro one tetramer of TTR can bind two molecules of retinol-binding protein. However, the concentration of RBP in the plasma is limiting, and the complex isolated from serum is composed of TTR and RBP in a 1 to 1 stoichiometry. We report here the crystallographic structure at 3.2 A of the protein-protein complex of human RBP and TTR. RBP binds at a 2-fold axis of symmetry in the TTR tetramer, and consequently the recognition site itself has 2-fold symmetry: Four TTR amino acids (Arg-21, Val-20, Leu-82, and Ile-84) are contributed by two monomers. Amino acids Trp-67, Phe-96, and Leu-63 and -97 from RBP are flanked by the symmetry-related side chains from TTR. In addition, the structure reveals an interaction of the carboxy terminus of RBP at the protein-protein recognition interface. This interaction, which involves Leu-182 and Leu-183 of RBP, is consistent with the observation that naturally occurring truncated forms of the protein are more readily cleared from plasma than full-length RBP. Complex formation prevents extensive loss of RBP through glomerular filtration, and the loss of Leu-182 and Leu-183 would result in a decreased affinity of RBP for TTR.


    Organizational Affiliation

    Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (transthyretin)
A, B, C, D
127Homo sapiensMutation(s): 0 
Gene Names: TTR (PALB)
Find proteins for P02766 (Homo sapiens)
Go to Gene View: TTR
Go to UniProtKB:  P02766
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (retinol binding protein)
E, F
180Homo sapiensMutation(s): 0 
Gene Names: RBP4
Find proteins for P02753 (Homo sapiens)
Go to Gene View: RBP4
Go to UniProtKB:  P02753
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
RTL
Query on RTL

Download SDF File 
Download CCD File 
E, F
RETINOL
C20 H30 O
FPIPGXGPPPQFEQ-OVSJKPMPSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.2 Å
  • R-Value Free: 0.403 
  • R-Value Work: 0.278 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 140.230α = 90.00
b = 140.230β = 90.00
c = 124.080γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
DENZOdata reduction
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-02-16
    Type: Initial release
  • Version 1.1: 2007-10-21
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance