Reviewed, UniProtKB/Swiss-Prot P00784 (PAPA1_CARPA)

Names and origin

Protein names	Recommended name:     Papain     EC=3.4.22.2 Alternative name(s):     Papaya proteinase I       Short name=PPI     Allergen=Car p 1
Organism	Carica papaya (Papaya)
Taxonomic identifier	3649 [NCBI]
Taxonomic lineage	Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › eurosids II › Brassicales › Caricaceae › Carica

Protein attributes

Sequence length	345 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level.

General annotation (Comments)

Catalytic activity	Hydrolysis of proteins with broad specificity for peptide bonds, but preference for an amino acid bearing a large hydrophobic side chain at the P2 position. Does not accept Val in P1'.
Allergenic properties	Causes an allergic reaction in human.
Sequence similarities	Belongs to the peptidase C1 family.

Ontologies

Keywords
Disease	Allergen
Domain	Signal
Molecular function	Hydrolase Protease Thiol protease
PTM	Disulfide bond Zymogen
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Biological process	proteolysis Inferred from electronic annotation. Source: InterPro
Molecular function	cysteine-type endopeptidase activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Signal peptide

1 – 18

18

Potential

Propeptide

19 – 133

115

Activation peptide Ref.2

PRO_0000026406

Chain

134 – 345

212

Papain

PRO_0000026407

Sites

Active site

158

1

Ref.4

Active site

292

1

Active site

308

1

Ref.4

Amino acid modifications

Disulfide bond

155 ↔ 196

Ref.2

Disulfide bond

189 ↔ 228

Ref.2

Disulfide bond

286 ↔ 333

Ref.2

Experimental info

Sequence conflict

180

1

E → Q AA sequence Ref.2

Sequence conflict

219 – 220

2

YP → PY AA sequence Ref.2

Sequence conflict

251

1

E → Q AA sequence Ref.2

Sequence conflict

268

1

E → Q AA sequence Ref.2

Secondary structure

1

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345

Helix Strand Turn

Details...

Helix

140 – 143

4

Beta strand

154 – 156

3

Helix

158 – 175

18

Helix

183 – 189

7

Beta strand

191 – 193

3

Helix

201 – 211

11

Turn

216 – 218

3

Turn

230 – 233

4

Beta strand

241 – 245

5

Helix

251 – 258

8

Beta strand

263 – 267

5

Helix

272 – 275

4

Beta strand

279 – 282

4

Beta strand

292 – 300

9

Beta strand

303 – 307

5

Beta strand

319 – 323

5

Helix

332 – 334

3

Beta strand

340 – 343

4

Sequences

	Sequence		Length	Mass (Da)
	P00784-1 [UniParc]. Last modified January 1, 1988. Version 1. Checksum: 82D9FB35EDCA12EF	FASTA	345	38,922
	10 20 30 40 50 60 MAMIPSISKL LFVAICLFVY MGLSFGDFSI VGYSQNDLTS TERLIQLFES WMLKHNKIYK 70 80 90 100 110 120 NIDEKIYRFE IFKDNLKYID ETNKKNNSYW LGLNVFADMS NDEFKEKYTG SIAGNYTTTE 130 140 150 160 170 180 LSYEEVLNDG DVNIPEYVDW RQKGAVTPVK NQGSCGSCWA FSAVVTIEGI IKIRTGNLNE 190 200 210 220 230 240 YSEQELLDCD RRSYGCNGGY PWSALQLVAQ YGIHYRNTYP YEGVQRYCRS REKGPYAAKT 250 260 270 280 290 300 DGVRQVQPYN EGALLYSIAN QPVSVVLEAA GKDFQLYRGG IFVGPCGNKV DHAVAAVGYG 310 320 330 340 PNYILIKNSW GTGWGENGYI RIKRGTGNSY GVCGLYTSSF YPVKN

References

[1]	"Cloning and sequencing of papain-encoding cDNA." Cohen L.W., Coghlan V.M., Dihel L.C. Gene 48:219-227(1986) [PubMed: 2881845] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"The complete amino acid sequence of papain. Additions and corrections." Mitchel R.E.J., Chaiken I.M., Smith E.L. J. Biol. Chem. 245:3485-3492(1970) [PubMed: 5470818] [Abstract] Cited for: PROTEIN SEQUENCE OF 134-345.
[3]	"A reinvestigation of residues 64-68 and 175 in papain. Evidence that residues 64 and 175 are asparagine." Husain S.S., Lowe G. Biochem. J. 116:689-692(1970) [PubMed: 5435495] [Abstract] Cited for: SEQUENCE REVISION TO 197.
[4]	"Structure of papain." Drenth J., Jansonius J.N., Koekoek R., Swen H.M., Wolthers B.G. Nature 218:929-932(1968) [PubMed: 5681232] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.8 ANGSTROMS).
[5]	"Structure of papain refined at 1.65-A resolution." Kamphuis I.G., Kalk K.H., Swarte M.B.A., Drenth J. J. Mol. Biol. 179:233-256(1984) [PubMed: 6502713] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.65 ANGSTROMS).
[6]	"The refined 2.4 A X-ray crystal structure of recombinant human stefin B in complex with the cysteine proteinase papain: a novel type of proteinase inhibitor interaction." Stubbs M.T., Laber B., Bode W., Huber R., Jerala R., Lenarcic B., Turk V. EMBO J. 9:1939-1947(1990) [PubMed: 2347312] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.4 ANGSTROMS).
[7]	"Crystal structure of papain-succinyl-Gln-Val-Val-Ala-Ala-p-nitroanilide complex at 1.7-A resolution: noncovalent binding mode of a common sequence of endogenous thiol protease inhibitors." Yamamoto A., Tomoo K., Doi M., Ohishi H., Inoue M., Ishida T., Yamamoto D., Tsuboi S., Okamoto H., Okada Y. Biochemistry 31:11305-11309(1992) [PubMed: 1445868] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS).
[8]	"Structure of monoclinic papain at 1.60-A resolution." Pickersgill R.W., Harris G.W., Garman E. Acta Crystallogr. B 48:59-67(1992) Cited for: X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS).
+	Additional computationally mapped references.

Web resources

Worthington enzyme manual

Cross-references

Sequence databases

EMBLGenBankDDBJ

M15203 mRNA. Translation: AAB02650.1.

PIR

PPPA. A26466.

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1BP4	X-ray	2.20	A	134-345	[»]
1BQI	X-ray	2.50	A	134-345	[»]
1CVZ	X-ray	1.70	A	134-345	[»]
1EFF	model	-	A	134-345	[»]
1KHP	X-ray	2.00	A	134-345	[»]
1KHQ	X-ray	1.60	A	134-345	[»]
1PAD	X-ray	2.80	A	134-345	[»]
1PE6	X-ray	2.10	A	134-345	[»]
1PIP	X-ray	1.70	A	134-345	[»]
1POP	X-ray	2.10	A	134-345	[»]
1PPD	X-ray	2.00	A	134-345	[»]
1PPN	X-ray	1.60	A	134-345	[»]
1PPP	X-ray	1.90	A	134-345	[»]
1STF	X-ray	2.37	E	134-345	[»]
2CIO	X-ray	1.50	A	134-345	[»]
2PAD	X-ray	2.80	A	134-345	[»]
3E1Z	X-ray	1.86	B	134-345	[»]
4PAD	X-ray	2.80	A	134-345	[»]
5PAD	X-ray	2.80	A	134-345	[»]
6PAD	X-ray	2.80	A	134-345	[»]
9PAP	X-ray	1.65	A	134-345	[»]

SMR

P00784. Positions 38-345.

ModBase

Search...

Protein family/group databases

MEROPS

C01.001.

Enzyme and pathway databases

BRENDA

3.4.22.2. 18730.

Family and domain databases

InterPro

IPR000169. Pept_cys_AS.
IPR013128. Peptidase_C1A.
IPR000668. Peptidase_C1A_C.
IPR013201. Prot_inhib_I29.
[Graphical view]

PANTHER

PTHR12411. Peptidase_C1A. 1 hit.

Pfam

PF08246. Inhibitor_I29. 1 hit.
PF00112. Peptidase_C1. 1 hit.
[Graphical view]

PRINTS

PR00705. PAPAIN.

ProDom

PD000158. Peptidase_C1. 1 hit.
[Graphical view] [Entries sharing at least one domain]

SMART

SM00645. Pept_C1. 1 hit.
[Graphical view]

PROSITE

PS00640. THIOL_PROTEASE_ASN. 1 hit.
PS00139. THIOL_PROTEASE_CYS. 1 hit.
PS00639. THIOL_PROTEASE_HIS. 1 hit.
[Graphical view]

ProtoNet

Search...

Other Resources

BindingDB

P00784.

Entry information

Entry name

PAPA1_CARPA

Accession

Primary (citable) accession number: P00784

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	January 1, 1988
Last modified:	June 16, 2009
This is version 89 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)