Scripps VIVO scripps research logo

  • Index
  • Log in
  • Home
  • People
  • Organizations
  • Research
  • Events
Search form

Nmr structures of 36 and 73-residue fragments of the calreticulin p-domain

Academic Article
uri icon
  • Overview
  • Research
  • Identity
  • Additional Document Info
  • View All
scroll to property group menus

Overview

authors

  • Ellgaard, L.
  • Bettendorff, P.
  • Braun, D.
  • Herrmann, T.
  • Fiorito, F.
  • Jelesarov, M.
  • Guntert, P.
  • Helenius, A.
  • Wuthrich, Kurt

publication date

  • September 2002

journal

  • Journal of Molecular Biology  Journal

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. 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.

subject areas

  • Amino Acid Sequence
  • Animals
  • Calreticulin
  • Computer Simulation
  • Gene Expression
  • Models, Molecular
  • Molecular Chaperones
  • Molecular Sequence Data
  • Nuclear Magnetic Resonance, Biomolecular
  • Peptide Fragments
  • Protein Structure, Tertiary
  • Rats
  • Solutions
scroll to property group menus

Research

keywords

  • ERp57
  • NMR structure
  • autonomous folding unit
  • calreticulin
  • endoplasmic reticulum
scroll to property group menus

Identity

International Standard Serial Number (ISSN)

  • 0022-2836

Digital Object Identifier (DOI)

  • 10.1016/s0022-2936(02)00812-4

PubMed ID

  • 12270713
scroll to property group menus

Additional Document Info

start page

  • 773

end page

  • 784

volume

  • 322

issue

  • 4

©2021 The Scripps Research Institute | Terms of Use | Powered by VIVO

  • About
  • Contact Us
  • Support