ID   SSIK_STRPT              Reviewed;         145 AA.
AC   O33702;
DT   24-OCT-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1998, sequence version 1.
DT   25-MAY-2022, entry version 85.
DE   RecName: Full=Kexstatin-1;
DE   AltName: Full=Kexstatin I;
DE   Flags: Precursor;
OS   Streptomyces platensis.
OC   Bacteria; Actinobacteria; Streptomycetales; Streptomycetaceae;
OC   Streptomyces.
OX   NCBI_TaxID=58346;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], CHARACTERIZATION, AND MUTAGENESIS OF
RP   THR-104 AND LYS-105.
RC   STRAIN=Q268;
RX   PubMed=11284720; DOI=10.1042/0264-6021:3550339;
RA   Oda K., Oyama H., Ito S., Fukiharu M., Miyagawa Y., Takahashi S.,
RA   Hirose M., Kikuchi N., Nakayama T., Shibano Y.;
RT   "Cloning and rational mutagenesis of kexstatin I, a potent proteinaceous
RT   inhibitor of Kex2 proteinase.";
RL   Biochem. J. 355:339-346(2001).
RN   [2]
RP   PARTIAL PROTEIN SEQUENCE, AND CHARACTERIZATION.
RC   STRAIN=Q268;
RX   PubMed=8987562; DOI=10.1271/bbb.60.1388;
RA   Oda K., Takahashi S., Kikuchi N., Shibano Y.;
RT   "A novel proteinaceous Kex 2 proteinase inhibitor, kexstatin, from
RT   Streptomyces platensis Q268.";
RL   Biosci. Biotechnol. Biochem. 60:1388-1389(1996).
CC   -!- FUNCTION: Strongly inhibits the kexin (KEX2) protease. Also active on
CC       subtilisin but not thermolysin, trypsin, or chymotrypsin.
CC   -!- SUBUNIT: Homodimer.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- SIMILARITY: Belongs to the protease inhibitor I16 (SSI) family.
CC       {ECO:0000305}.
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DR   EMBL; AB005264; BAA21112.1; -; Genomic_DNA.
DR   AlphaFoldDB; O33702; -.
DR   SMR; O33702; -.
DR   MEROPS; I16.002; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-UniRule.
DR   Gene3D; 3.30.350.10; -; 1.
DR   HAMAP; MF_00778; SSI; 1.
DR   InterPro; IPR000691; Prot_inh_I16_SSI.
DR   InterPro; IPR020054; Prot_inh_SSI_I16_CS.
DR   InterPro; IPR023549; Subtilisin_inhibitor.
DR   InterPro; IPR036819; Subtilisin_inhibitor-like_sf.
DR   Pfam; PF00720; SSI; 1.
DR   PRINTS; PR00294; SSBTLNINHBTR.
DR   SUPFAM; SSF55399; SSF55399; 1.
DR   PROSITE; PS00999; SSI; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Protease inhibitor; Secreted;
KW   Serine protease inhibitor; Signal.
FT   SIGNAL          1..25
FT                   /evidence="ECO:0000255"
FT   PROPEP          26..35
FT                   /id="PRO_0000033276"
FT   CHAIN           36..145
FT                   /note="Kexstatin-1"
FT                   /id="PRO_0000033277"
FT   SITE            105..106
FT                   /note="Reactive bond"
FT   DISULFID        66..81
FT                   /evidence="ECO:0000250"
FT   DISULFID        103..133
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   145 AA;  15125 MW;  80F74226735FE0DA CRC64;
     MRYITGAVAL GAALVLGTLA TTAQAAAPAQ PARTGGLYAP TELVLTVGQG ESRATATVQR
     AVTLSCMPGA RGSHPNPLGA CTQLRAVAGD FNAITAATSD RLCTKEWNPL VVTADGVWQG
     KRVSYSYTFA NRCEMNIDSD TVFNF