PDBsum entry 6mcu

Lipid binding protein

PDB id: 6mcu

Contents

Protein chains

(+ 6 more) 133 a.a.

Ligands

GOL ×3

RET ×5

Waters ×149

PDB id:

6mcu

Name:

Lipid binding protein

Title:

Crystal structure of the holo retinal-bound domain-swapped dimer q108k:t51d:a28h mutant of human cellular retinol binding protein ii

Structure:

Retinol-binding protein 2. Chain: a, b, c, d, e, f, g, h, i, j, k, l. Synonym: cellular retinol-binding protein ii,crbp-ii. Engineered: yes. Mutation: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: rbp2, crbp2. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

2.57Å R-factor: 0.233 R-free: 0.296

Authors:

A.Ghanbarpour,J.Geiger

Key ref:

A.Ghanbarpour et al. (2019). Engineering the hCRBPII Domain-Swapped Dimer into a New Class of Protein Switches. J Am Chem Soc, 141, 17125-17132. PubMed id: 31557439 DOI: 10.1021/jacs.9b04664

Date:

02-Sep-18 Release date: 16-Oct-19

Protein chains

P50120  (RET2_HUMAN) -  Retinol-binding protein 2 from Homo sapiens

Seq: 134 a.a.

Struc: 133 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

DOI no: 10.1021/jacs.9b04664

J Am Chem Soc 141:17125-17132 (2019)

PubMed id: 31557439

Engineering the hCRBPII Domain-Swapped Dimer into a New Class of Protein Switches.

A.Ghanbarpour, C.Pinger, R.Esmatpour Salmani, Z.Assar, E.M.Santos, M.Nosrati, K.Pawlowski, D.Spence, C.Vasileiou, X.Jin, B.Borhan, J.H.Geiger.

ABSTRACT

Protein conformational switches or allosteric proteins play a key role in the regulation of many essential biological pathways. Nonetheless, the implementation of protein conformational switches in protein design applications has proven challenging, with only a few known examples that are not derivatives of naturally occurring allosteric systems. We have discovered that the domain-swapped (DS) dimer of hCRBPII undergoes a large and robust conformational change upon retinal binding, making it a potentially powerful template for the design of protein conformational switches. Atomic resolution structures of the apo- and holo-forms illuminate a simple, mechanical movement involving sterically driven torsion angle flipping of two residues that drive the motion. We further demonstrate that the conformational "readout" can be altered by addition of cross-domain disulfide bonds, also visualized at atomic resolution. Finally, as a proof of principle, we have created an allosteric metal binding site in the DS dimer, where ligand binding results in a reversible 5-fold loss of metal binding affinity. The high resolution structure of the metal-bound variant illustrates a well-formed metal binding site at the interface of the two domains of the DS dimer and confirms the design strategy for allosteric regulation.