1K91

Solution Structure of Calreticulin P-domain subdomain (residues 221-256)


Experimental Data Snapshot

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

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This is version 1.3 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

  • DOI: 10.1016/s0022-2836(02)00812-4
  • Primary Citation of Related Structures:  
    1K91, 1K9C

  • 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 with an associated co-chaperone, the thiol-disulfide oxidoreductase ERp57 ...

    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:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CALRETICULINA37Rattus norvegicusMutation(s): 0 
Gene Names: Calr
UniProt
Find proteins for P18418 (Rattus norvegicus)
Explore P18418 
Go to UniProtKB:  P18418
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP18418
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 
  • OLDERADO: 1K91 Olderado

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2002-10-12
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-02-23
    Changes: Data collection, Database references, Derived calculations