ID   SPI4_SOLTU              Reviewed;         103 AA.
AC   P58517;
DT   23-JAN-2002, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2002, sequence version 1.
DT   03-AUG-2022, entry version 75.
DE   RecName: Full=Serine protease inhibitor 4;
DE            Short=PI-4;
DE   Flags: Fragment;
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.
RC   STRAIN=cv. Pentland squire; TISSUE=Tuber;
RX   PubMed=1515078; DOI=10.1515/bchm3.1992.373.2.477;
RA   Strukelj B., Pungercar J., Mesko P., Barlic-Maganja D., Gubensek F.,
RA   Kregar I., Turk V.;
RT   "Characterization of aspartic proteinase inhibitors from potato at the
RT   gene, cDNA and protein levels.";
RL   Biol. Chem. Hoppe-Seyler 373:477-482(1992).
CC   -!- FUNCTION: Inhibitor of serine protease. May protect the plant by
CC       inhibiting proteases of invading organisms (By similarity).
CC       {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Vacuole {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the protease inhibitor I3 (leguminous Kunitz-
CC       type inhibitor) family. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   PIR; S24187; S24187.
DR   AlphaFoldDB; P58517; -.
DR   SMR; P58517; -.
DR   PRIDE; P58517; -.
DR   Proteomes; UP000011115; Unassembled WGS sequence.
DR   ExpressionAtlas; P58517; baseline.
DR   GO; GO:0005773; C:vacuole; IEA:UniProtKB-SubCell.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
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.
PE   3: Inferred from homology;
KW   Disulfide bond; Protease inhibitor; Reference proteome;
KW   Serine protease inhibitor; Vacuole.
FT   CHAIN           <1..103
FT                   /note="Serine protease inhibitor 4"
FT                   /id="PRO_0000016903"
FT   SITE            25..26
FT                   /note="Reactive bond for chymotrypsin"
FT                   /evidence="ECO:0000250"
FT   DISULFID        56..73
FT                   /evidence="ECO:0000250"
FT   NON_TER         1
SQ   SEQUENCE   103 AA;  11349 MW;  D328692B166B21C4 CRC64;
     ISTSKLCVSY TIWKVGDYDA SLGTMLLETG GTIGQADSSW FKIVQSSQFG YNLLYCPVTS
     TMSCPFSLDD QFCLKVGVVH QNGKRRLALV NGNPLECLFK QVQ