PDBsum entry 6t1r

Chaperone

PDB id: 6t1r

Contents

Protein chains

(+ 10 more) 166 a.a.

PDB id:

6t1r

Name:

Chaperone

Title:

Pseudo-atomic model of a 16-mer assembly of reduced recombinant human alphaa-crystallin (non domain swapped configuration)

Structure:

Alpha-crystallin a chain. Chain: a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p. Synonym: heat shock protein beta-4,hspb4. Engineered: yes. Other_details: wild type residues 1-166

Source:

Homo sapiens. Human. Organism_taxid: 9606. Organ: eye. Tissue: lens. Gene: cryaa, crya1, hspb4. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693. Expression_system_variant: codonplus-ril.

Authors:

C.Peters,C.J.O.Kaiser,S.Weinkauf,M.Zacharias,J.Buchner

Key ref:

C.J.O.Kaiser et al. (2019). The structure and oxidation of the eye lens chaperone αA-crystallin. Nat Struct Mol Biol, 26, 1141-1150. PubMed id: 31792453 DOI: 10.1038/s41594-019-0332-9

Date:

05-Oct-19 Release date: 11-Dec-19

Protein chains

P02489  (CRYAA_HUMAN) -  Alpha-crystallin A chain from Homo sapiens

Seq: 173 a.a.

Struc: 166 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1038/s41594-019-0332-9

Nat Struct Mol Biol 26:1141-1150 (2019)

PubMed id: 31792453

The structure and oxidation of the eye lens chaperone αA-crystallin.

C.J.O.Kaiser, C.Peters, P.W.N.Schmid, M.Stavropoulou, J.Zou, V.Dahiya, E.V.Mymrikov, B.Rockel, S.Asami, M.Haslbeck, J.Rappsilber, B.Reif, M.Zacharias, J.Buchner, S.Weinkauf.

ABSTRACT

The small heat shock protein αA-crystallin is a molecular chaperone important for the optical properties of the vertebrate eye lens. It forms heterogeneous oligomeric ensembles. We determined the structures of human αA-crystallin oligomers by combining cryo-electron microscopy, cross-linking/mass spectrometry, NMR spectroscopy and molecular modeling. The different oligomers can be interconverted by the addition or subtraction of tetramers, leading to mainly 12-, 16- and 20-meric assemblies in which interactions between N-terminal regions are important. Cross-dimer domain-swapping of the C-terminal region is a determinant of αA-crystallin heterogeneity. Human αA-crystallin contains two cysteines, which can form an intramolecular disulfide in vivo. Oxidation in vitro requires conformational changes and oligomer dissociation. The oxidized oligomers, which are larger than reduced αA-crystallin and destabilized against unfolding, are active chaperones and can transfer the disulfide to destabilized substrate proteins. The insight into the structure and function of αA-crystallin provides a basis for understanding its role in the eye lens.