2CIO: Papain

The high resolution x-ray structure of papain complexed with fragments of the Trypanosoma brucei cysteine protease inhibitor ICP. Determined by X-ray diffraction at 1.5 Å resolution. Released 18 May 2006.

Method: X-ray diffraction
Resolution: 1.5 Å
Organisms: CARICA PAPAYA, TRYPANOSOMA BRUCEI
Chains: 2
Atoms: 1,974
Mol. weight: 37.31 kDa
Released: 18 May 2006

Explore 2CIO in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

2CIO contains 8 α-helices and 17 β-strands across 1 chain. 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: 8 helices, 17 β-strands

Element	Residues	Length	Sheet
β-strand	5-6	2	1
α-helix	14-16	3
β-strand	18	1	2
β-strand	23	1	3
α-helix	25-42	18
β-strand	48	1	4
α-helix	50-56	7
β-strand	64	1	3
α-helix	68-77	10
β-strand	80	1	5
β-strand	82	1	4
β-strand	105	1	5
β-strand	109-112	4	1
α-helix	113-114	2
α-helix	118-127	10
β-strand	130-134	5	1
α-helix	139-142	4
β-strand	148-149	2	1
β-strand	159-167	9	1
β-strand	170-174	5	1
β-strand	177	1	2
β-strand	183	1	1
β-strand	186-190	5	1
α-helix	199-201	3
β-strand	207-210	4	1

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Papain	A	protein	212	CARICA PAPAYA	P00784 (AlphaFold model)
Inhibitor of cysteine peptidase	B	protein	121	TRYPANOSOMA BRUCEI	Q868H0 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>2CIO_1 PAPAIN (chains A)
IPEYVDWRQKGAVTPVKNQGSCGSCWAFSAVVTIEGIIKIRTGNLNQYSEQELLDCDRRS
YGCNGGYPWSALQLVAQYGIHYRNTYPYEGVQRYCRSREKGPYAAKTDGVRQVQPYNEGA
LLYSIANQPVSVVLEAAGKDFQLYRGGIFVGPCGNKVDHAVAAVGYGPNYILIKNSWGTG
WGENGYIRIKRGTGNSYGVCGLYTSSFYPVKN

Sequence of entity 2 (B), FASTA

>2CIO_2 INHIBITOR OF CYSTEINE PEPTIDASE (chains B)
MSHNLFTEEDNNKTIRMVIGETFTIELESNPTTGYTWLRSGLAGTELSDCTFAIQSKFNN
RAPHDNHKNHRRLLVGAGGTMVLEVKALKAGKHTLSLAYGRPWVGFNAAAKRYNIHVEAT
A

Primary citation

High-Resolution Complex of Papain with Remnants of a Cysteine Protease Inhibitor Derived from Trypanosoma Brucei. Alphey, M.S., Hunter, W.N. Acta Crystallogr Sect F Struct Biol Cryst Commun (2006) 62:504. DOI 10.1107/S1744309106014849 · PubMed

Other PDB entries of the same protein (UniProt P00784 (AlphaFold model), which also has an AlphaFold model), best resolution first:

9CKW 1.4 Å, X-ray diffraction structure of papain co-crystallized with E-64D
9CKY 1.4 Å, X-ray diffraction structure of papain co-crystallized with novel biosynthetic inhibitor…
9CKT 1.5 Å, X-ray diffraction structure of papain co-crystallized with E-64
9EG7 1.5 Å, X-ray diffraction structure of papain co-crystallized with E64-C
9NB2 1.5 Å, X-ray diffraction structure of papain soaked with E-64
1KHQ 1.6 Å, Orthorhombic form of papain/zlfg-dam covalent complex
1PPN 1.6 Å, Structure of monoclinic papain at 1.60 Å resolution
9CLH 1.6 Å, X-ray diffraction structure of the apo form of papain
9NAT 1.6 Å, X-ray diffraction structure of papain co-crystallized with leupeptin
6TCX 1.65 Å, Papain bound to a natural cysteine protease inhibitor from Streptomyces mobaraensis
9PAP 1.65 Å, Structure of papain refined at 1.65 Å resolution
1CVZ 1.7 Å, Crystal structure analysis of papain with CLIK148(CATHEPSIN L specific inhibitor)

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