ID   API4_SOLTU              Reviewed;         220 AA.
AC   Q43645;
DT   23-JAN-2002, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2002, sequence version 2.
DT   03-AUG-2022, entry version 92.
DE   RecName: Full=Aspartic protease inhibitor 4;
DE   AltName: Full=API-13;
DE            Short=PI13;
DE   Flags: Precursor;
OS   Solanum tuberosum (Potato).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Solanales; Solanaceae; Solanoideae; Solaneae; Solanum.
OX   NCBI_TaxID=4113;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=cv. Ulster Sceptre; TISSUE=Tuber;
RX   PubMed=9055446; DOI=10.1016/s0031-9422(96)00668-1;
RA   Kreft S., Ravnikar M., Mesko P., Pungercar J., Umek A., Kregar I.,
RA   Strukelj B.;
RT   "Jasmonic acid inducible aspartic proteinase inhibitors from potato.";
RL   Phytochemistry 44:1001-1006(1997).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA] OF 5-220.
RC   STRAIN=cv. Ulster Sceptre; TISSUE=Tuber;
RX   PubMed=8540331; DOI=10.1007/978-1-4615-1871-6_35;
RA   Strukelj B., Ravnikar M., Mesko P., Poljsak-Prijatelj M., Pungercar J.,
RA   Kopitar G., Kregar I., Turk V.;
RT   "Molecular cloning and immunocytochemical localization of jasmonic acid
RT   inducible cathepsin D inhibitors from potato.";
RL   Adv. Exp. Med. Biol. 362:293-298(1995).
CC   -!- FUNCTION: Inhibits tightly cathepsin D (aspartic protease) and weakly
CC       trypsin (serine protease). May protect the plant by inhibiting
CC       proteases of invading organisms.
CC   -!- SUBCELLULAR LOCATION: Vacuole {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Tubers.
CC   -!- INDUCTION: By jasmonate.
CC   -!- SIMILARITY: Belongs to the protease inhibitor I3 (leguminous Kunitz-
CC       type inhibitor) family. {ECO:0000305}.
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DR   EMBL; X62095; CAA44005.1; -; mRNA.
DR   AlphaFoldDB; Q43645; -.
DR   SMR; Q43645; -.
DR   MEROPS; I03.002; -.
DR   PRIDE; Q43645; -.
DR   Proteomes; UP000011115; Unassembled WGS sequence.
DR   ExpressionAtlas; Q43645; baseline.
DR   GO; GO:0005773; C:vacuole; IEA:UniProtKB-SubCell.
DR   GO; GO:0019828; F:aspartic-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   CDD; cd00178; STI; 1.
DR   InterPro; IPR011065; Kunitz_inhibitor_STI-like_sf.
DR   InterPro; IPR002160; Prot_inh_Kunz-lg.
DR   PANTHER; PTHR33107; PTHR33107; 1.
DR   Pfam; PF00197; Kunitz_legume; 1.
DR   PRINTS; PR00291; KUNITZINHBTR.
DR   SMART; SM00452; STI; 1.
DR   SUPFAM; SSF50386; SSF50386; 1.
DR   PROSITE; PS00283; SOYBEAN_KUNITZ; 1.
PE   2: Evidence at transcript level;
KW   Aspartic protease inhibitor; Disulfide bond; Glycoprotein;
KW   Protease inhibitor; Reference proteome; Serine protease inhibitor; Signal;
KW   Vacuole.
FT   SIGNAL          1..23
FT                   /evidence="ECO:0000250"
FT   PROPEP          24..32
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000016914"
FT   CHAIN           33..220
FT                   /note="Aspartic protease inhibitor 4"
FT                   /id="PRO_0000016915"
FT   MOTIF           26..31
FT                   /note="Vacuolar targeting signal"
FT                   /evidence="ECO:0000250"
FT   SITE            99..100
FT                   /note="Reactive bond for trypsin"
FT                   /evidence="ECO:0000250"
FT   SITE            143..144
FT                   /note="Reactive bond for chymotrypsin"
FT                   /evidence="ECO:0000250"
FT   CARBOHYD        51
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   DISULFID        80..125
FT                   /evidence="ECO:0000250"
FT   DISULFID        174..185
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   220 AA;  24375 MW;  1759B3DDF085A201 CRC64;
     MMKCLFLLCL CLLPILVFSS TFTSQNPINL PSESPVPKPV LDTNGKELNP NSSYRIISIG
     RGALGGDVYL GKSPNSDAPC PDGVFRYNSD VGPSGTPVRF IPLSTNIFED QLLNIQFNIP
     TVKLCVSYRN WKVGNLNAHL WTMLLETGGT IGQADSSYFK IVKSSKFGYN LLYCPITRHF
     LCPFCRDDNF CAKVGVDIQN GKRRLALVSE NPLDVLFQEV