1k91: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1k91.jpg|left|200px]] | [[Image:1k91.jpg|left|200px]] | ||
<!-- | |||
The line below this paragraph, containing "STRUCTURE_1k91", creates the "Structure Box" on the page. | |||
You may change the PDB parameter (which sets the PDB file loaded into the applet) | |||
or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |||
or leave the SCENE parameter empty for the default display. | |||
--> | |||
{{STRUCTURE_1k91| PDB=1k91 | SCENE= }} | |||
}} | |||
'''Solution Structure of Calreticulin P-domain subdomain (residues 221-256)''' | '''Solution Structure of Calreticulin P-domain subdomain (residues 221-256)''' | ||
| Line 33: | Line 30: | ||
[[Category: Herrmann, T.]] | [[Category: Herrmann, T.]] | ||
[[Category: Wuthrich, K.]] | [[Category: Wuthrich, K.]] | ||
[[Category: | [[Category: Hairpin]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 22:27:16 2008'' | |||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | |||
Revision as of 22:27, 2 May 2008
Solution Structure of Calreticulin P-domain subdomain (residues 221-256)
OverviewOverview
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.
About this StructureAbout this Structure
1K91 is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
ReferenceReference
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, J Mol Biol. 2002 Sep 27;322(4):773-84. PMID:12270713 Page seeded by OCA on Fri May 2 22:27:16 2008