1GGL

HUMAN CELLULAR RETINOL BINDING PROTEIN III

Summary for 1GGL

• Entry DOI: 10.2210/pdb1ggl/pdb
• Descriptor: PROTEIN (CELLULAR RETINOL-BINDING PROTEIN III) (2 entities in total)
• Functional Keywords: carrier, retinol binding protein, transport protein
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 2
• Total formula weight: 31606.00

Authors

Calderone, V.,Zanotti, G.,Folli, C.,Ottonello, S.,Bolchi, A.,Stoppini, M.,Berni, R. (deposition date: 2000-08-23, release date: 2001-03-07, Last modification date: 2023-08-09)

Primary citation

Folli, C.,Calderone, V.,Ottonello, S.,Bolchi, A.,Zanotti, G.,Stoppini, M.,Berni, R.
Identification, retinoid binding, and x-ray analysis of a human retinol-binding protein.
Proc.Natl.Acad.Sci.USA, 98:3710-3715, 2001

PubMed Abstract: Two cellular retinol-binding proteins (CRBP I and II) with distinct tissue distributions and retinoid-binding properties have been recognized thus far in mammals. Here, we report the identification of a human retinol-binding protein resembling type I (55.6% identity) and type II (49.6% identity) CRBPs, but with a unique H residue in the retinoid-binding site and a distinctively different tissue distribution. Additionally, this binding protein (CRBP III) exhibits a remarkable sequence identity (62.2%) with the recently identified iota-crystallin/CRBP of the diurnal gecko Lygodactylus picturatus [Werten, P. J. L., Röll, B., van Alten, D. M. F. & de Jong, W. W. (2000) Proc. Natl. Acad. Sci. USA 97, 3282-3287 (First Published March 21, 2000; 10.1073/pnas.050500597)]. CRBP III and all-trans-retinol form a complex (K(d) approximately 60 nM), the absorption spectrum of which is characterized by the peculiar fine structure typical of the spectra of holo-CRBP I and II. As revealed by a 2.3-A x-ray molecular model of apo-CRBP III, the amino acid residues that line the retinol-binding site in CRBP I and II are positioned nearly identically in the structure of CRBP III. At variance with the human CRBP I and II mRNAs, which are most abundant in ovary and intestine, respectively, the CRBP III mRNA is expressed at the highest levels in kidney and liver thus suggesting a prominent role for human CRBP III as an intracellular mediator of retinol metabolism in these tissues.

PubMed: 11274389
DOI: 10.1073/pnas.061455898

Experimental method

X-RAY DIFFRACTION (2.31 Å)