1K9C

Solution Structure of Calreticulin P-domain subdomain (residues 189-261)


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

NMR Structures of 36 and 73-residue Fragments of the Calreticulin P-domain

Ellgaard, L.Bettendorff, P.Braun, D.Herrmann, T.Fiorito, F.Jelesarov, I.Guntert, P.Helenius, A.Wuthrich, K.

(2002) J.Mol.Biol. 322: 773-784

  • Primary Citation of Related Structures:  1K91

  • PubMed Abstract: 
  • Calreticulin (CRT) is an abundant, soluble molecular chaperone of the endoplasmic reticulum. Similar to its membrane-bound homolog calnexin (CNX), it is a lectin that promotes the folding of proteins carrying N-linked glycans. Both proteins cooperate ...

    Calreticulin (CRT) is an abundant, soluble molecular chaperone of the endoplasmic reticulum. Similar to its membrane-bound homolog calnexin (CNX), it is a lectin that promotes the folding of proteins carrying N-linked glycans. Both proteins cooperate with an associated co-chaperone, the thiol-disulfide oxidoreductase ERp57. This enzyme catalyzes the formation of disulfide bonds in CNX and CRT-bound glycoprotein substrates. Previously, we solved the NMR structure of the central proline-rich P-domain of CRT comprising residues 189-288. This structure shows an extended hairpin topology, with three short anti-parallel beta-sheets, three small hydrophobic clusters, and one helical turn at the tip of the hairpin. We further demonstrated that the residues 225-251 at the tip of the CRT P-domain are involved in direct contacts with ERp57. Here, we show that the CRT P-domain fragment CRT(221-256) constitutes an autonomous folding unit, and has a structure highly similar to that of the corresponding region in CRT(189-288). Of the 36 residues present in CRT(221-256), 32 form a well-structured core, making this fragment one of the smallest known natural sequences to form a stable non-helical fold in the absence of disulfide bonds or tightly bound metal ions. CRT(221-256) comprises all the residues of the intact P-domain that were shown to interact with ERp57. Isothermal titration microcalorimetry (ITC) now showed affinity of this fragment for ERp57 similar to that of the intact P-domain, demonstrating that CRT(221-256) may be used as a low molecular mass mimic of CRT for further investigations of the interaction with ERp57. We also solved the NMR structure of the 73-residue fragment CRT(189-261), in which the tip of the hairpin and the first beta-sheet are well structured, but the residues 189-213 are disordered, presumably due to lack of stabilizing interactions across the hairpin.


    Organizational Affiliation

    Institut für Biochemie, Eidgenössische Technische Hochschule Zürich, Switzerland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CALRETICULIN
A
74Rattus norvegicusGene Names: Calr
Find proteins for P18418 (Rattus norvegicus)
Go to UniProtKB:  P18418
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 
  • Olderado: 1K9C Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-10-12
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance