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: 3.20 Å
  • R-Value Free: 0.403 
  • R-Value Work: 0.278 

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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
  • Primary Citation of Related Structures:  
    1QAB

  • 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, previously referred to as thyroxine-binding prealbumin) ...

    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:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
PROTEIN (transthyretin)A, B, C, D127Homo sapiensMutation(s): 0 
Gene Names: TTRPALB
UniProt & NIH Common Fund Data Resources
Find proteins for P02766 (Homo sapiens)
Explore P02766 
Go to UniProtKB:  P02766
PHAROS:  P02766
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
PROTEIN (retinol binding protein)E, F180Homo sapiensMutation(s): 0 
Gene Names: RBP4PRO2222
UniProt & NIH Common Fund Data Resources
Find proteins for P02753 (Homo sapiens)
Explore P02753 
Go to UniProtKB:  P02753
PHAROS:  P02753
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
RTL (Subject of Investigation/LOI)
Query on RTL

Download Ideal Coordinates CCD File 
G [auth E], H [auth F]RETINOL
C20 H30 O
FPIPGXGPPPQFEQ-OVSJKPMPSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.20 Å
  • R-Value Free: 0.403 
  • R-Value Work: 0.278 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 140.23α = 90
b = 140.23β = 90
c = 124.08γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
CNSrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

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