1CIQ: Chymotrypsin inhibitor 2

Complex of two fragments of CI2, residues 1-40 and 41-64. Determined by X-ray diffraction at 2.2 Å resolution. Released 8 Mar 1996.

Method: X-ray diffraction
Resolution: 2.2 Å
Organism: Hordeum vulgare
Chains: 2
Atoms: 535
Mol. weight: 7.33 kDa
Released: 8 Mar 1996

Explore 1CIQ in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

1CIQ contains 2 α-helices and 7 β-strands across 2 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chain A: 2 helices, 3 β-strands

Element	Residues	Length	Sheet
β-strand	4	1	1
α-helix	6-8	3
β-strand	12	1	2
α-helix	13-23	11
β-strand	28-33	6	1

Chain B: 0 helices, 4 β-strands

Element	Residues	Length	Sheet
β-strand	46-51	6	1
β-strand	56	1	2
β-strand	57	1	1
β-strand	62-63	2	1

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Chymotrypsin inhibitor 2	A	protein	40	Hordeum vulgare	P01053 (AlphaFold model)
Chymotrypsin inhibitor 2	B	protein	24	Hordeum vulgare	P01053 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>1CIQ_1 CHYMOTRYPSIN INHIBITOR 2 (chains A)
MKTEWPELVGKSVEEAKKVILQDKPEAQIIVLPVGTIVTM

Sequence of entity 2 (B), FASTA

>1CIQ_2 CHYMOTRYPSIN INHIBITOR 2 (chains B)
EYRIDRVRLFVDKLDNIAQVPRVG

Primary citation

Towards the complete structural characterization of a protein folding pathway: the structures of the denatured, transition and native states for the association/folding of two complementary fragments of cleaved chymotrypsin inhibitor 2. Direct evidence for a nucleation-condensation mechanism. Neira, J.L., Davis, B., Ladurner, A.G. et al. Structure (1996) 1:189-208. DOI 10.1016/S1359-0278(96)00031-4 · PubMed

Other PDB entries of the same protein (UniProt P01053 (AlphaFold model), which also has an AlphaFold model), best resolution first:

7A3M 1.01 Å, Synergistic stabilization of a double mutant in CI2 from an in-cell library screen
7AON 1.3 Å, Crystal structure of CI2 double mutant L49I,I57V
1LW6 1.5 Å, Crystal Structure of the Complex of Subtilisin BPN' with Chymotrypsin Inhibitor 2 at 1.5…
6QIY 1.5 Å, CI-2, conformation 1
6QIZ 1.65 Å, CI-2, conformation 2
1YPC 1.7 Å, Direct observation of better hydration at the N-terminus of an alpha-helix with glycine…
1CQ4 1.8 Å, CI2 mutant with tetraglutamine (mgqqqqgm) replacing MET59
5FFN 1.8 Å, Complex of subtilase SubTY from Bacillus sp. TY145 with chymotrypsin inhibitor CI2A
7AOK 1.87 Å, Crystal structure of CI2 mutant L49I
5FBZ 1.9 Å, Structure of subtilase SubHal from Bacillus halmapalus - complex with chymotrypsin…
7A1H 1.9 Å, Crystal structure of wild-type CI2
1YPA 2.0 Å, Direct observation of better hydration at the N-terminus of an alpha-helix with glycine…

Browse structure collections

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