1CQ4 image
Entry Detail
PDB ID:
1CQ4
Title:
CI2 MUTANT WITH TETRAGLUTAMINE (MGQQQQGM) REPLACING MET59
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
1998-11-17
Release Date:
1998-11-25
Method Details:
Experimental Method:
Resolution:
1.80 Å
R-Value Free:
0.30
R-Value Work:
0.24
Space Group:
P 6 2 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:PROTEIN (SERINE PROTEINASE INHIBITOR 2)
Mutations:YES
Chain IDs:A
Chain Length:47
Number of Molecules:1
Biological Source:Hordeum vulgare
Polymer Type:polypeptide(L)
Description:PROTEIN (SERINE PROTEINASE INHIBITOR 2)
Mutations:YES
Chain IDs:B
Chain Length:24
Number of Molecules:1
Biological Source:Hordeum vulgare
Ligand Molecules
Primary Citation
Crystal structure of a dimeric chymotrypsin inhibitor 2 mutant containing an inserted glutamine repeat.
Proc.Natl.Acad.Sci.USA 96 1257 1261 (1999)
PMID: 9990011 DOI: 10.1073/pnas.96.4.1257

Abstact

We have constructed mutants of chymotrypsin inhibitor 2 with short glutamine repeats inserted into its inhibitory loop. These mutants oligomerize when expressed in Escherichia coli. The dimer of a mutant with four glutamines now has been crystallized, and its structure has been solved by molecular replacement by using the wild-type monomer as a search model. The structure of each half of the dimer is found to be the same as that of the wild-type monomer, except around the glutamine insertion. It was proposed that the components of the oligomers are held together by hydrogen bonds between the main-chain and side-chain amides of the glutamine repeats. Instead, they appear to form by swapping domains on folding in E. coli, and the glutamine repeats connecting the components of the dimers are disordered.

Legend

Protein

Chemical

Disease

Primary Citation of related structures