PDBsum entry 6mqw

Lipid binding protein

PDB id: 6mqw

Contents

Protein chain

137 a.a.

Ligands

RET

Waters ×54

PDB id:

6mqw

Name:

Lipid binding protein

Title:

Crystal structure of all-trans retinal-bound r111k:y134f:t54v:r132q:p39y:r59y:l121e human cellular retinoic acid binding protein ii irradiated with 400 nm laser (30 seconds) and subsequently dark adapted (10 minutes) at 2.1 angstrom resolution

Structure:

Cellular retinoic acid-binding protein 2. Chain: a. Synonym: cellular retinoic acid-binding protein ii,crabp-ii. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: crabp2. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

2.09Å R-factor: 0.187 R-free: 0.220

Authors:

A.Ghanbarpour,J.Geiger

Key ref:

A.Ghanbarpour et al. (2019). Mimicking Microbial Rhodopsin Isomerization in a Single Crystal. J Am Chem Soc, 141, 1735-1741. PubMed id: 30580520 DOI: 10.1021/jacs.8b12493

Date:

11-Oct-18 Release date: 09-Jan-19

Protein chain

P29373  (RABP2_HUMAN) -  Cellular retinoic acid-binding protein 2 from Homo sapiens

Seq: 138 a.a.

Struc: 137 a.a.*

* PDB and UniProt seqs differ at 7 residue positions (black crosses)

DOI no: 10.1021/jacs.8b12493

J Am Chem Soc 141:1735-1741 (2019)

PubMed id: 30580520

Mimicking Microbial Rhodopsin Isomerization in a Single Crystal.

A.Ghanbarpour, M.Nairat, M.Nosrati, E.M.Santos, C.Vasileiou, M.Dantus, B.Borhan, J.H.Geiger.

ABSTRACT

Bacteriorhodopsin represents the simplest, and possibly most abundant, phototropic system requiring only a retinal-bound transmembrane protein to convert photons of light to an energy-generating proton gradient. The creation and interrogation of a microbial rhodopsin mimic, based on an orthogonal protein system, would illuminate the design elements required to generate new photoactive proteins with novel function. We describe a microbial rhodopsin mimic, created using a small soluble protein as a template, that specifically photoisomerizes all- trans to 13- cis retinal followed by thermal relaxation to the all- trans isomer, mimicking the bacteriorhodopsin photocycle, in a single crystal. The key element for selective isomerization is a tuned steric interaction between the chromophore and protein, similar to that seen in the microbial rhodopsins. It is further demonstrated that a single mutation converts the system to a protein photoswitch without chromophore photoisomerization or conformational change.