4CJ6: Crystal Structure Of The Complex Of The Cellular Retinal Binding Protein Mutant R234w With 9-cis-retinal

Citation:
Abstract
Cellular retinaldehyde-binding protein (CRALBP) chaperones 11-cis-retinal to convert opsin receptor molecules into photosensitive retinoid pigments of the eye. We report a thermal secondary isomerase activity of CRALBP when bound to 9-cis-retinal. UV/vis and (1)H NMR spectroscopy were used to characterize the product as 9,13-dicis-retinal. The X-ray structure of the CRALBP mutant R234W:9-cis-retinal complex at 1.9 A resolution revealed a niche in the binding pocket for 9-cis-aldehyde different from that reported for 11-cis-retinal. Combined computational, kinetic, and structural data lead us to propose an isomerization mechanism catalyzed by a network of buried waters. Our findings highlight a specific role of water molecules in both CRALBP-assisted specificity toward 9-cis-retinal and its thermal isomerase activity yielding 9,13-dicis-retinal. Kinetic data from two point mutants of CRALBP support an essential role of Glu202 as the initial proton donor in this isomerization reaction.
PDB ID: 4CJ6Download
MMDB ID: 116484
PDB Deposition Date: 2013/12/19
Updated in MMDB: 2014/01
Experimental Method:
x-ray diffraction
Resolution: 1.9  Å
Source Organism:
Similar Structures:
Biological Unit for 4CJ6: monomeric; determined by software (PISA)
Molecular Components in 4CJ6
Label Count Molecule
Protein (1 molecule)
1
Retinaldehyde-binding Protein 1(Gene symbol: RLBP1)
Molecule annotation
Chemical (1 molecule)
1
1
* Click molecule labels to explore molecular sequence information.

Citing MMDB
.