ID   SSI_STRAO               Reviewed;         144 AA.
AC   P01006;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1990, sequence version 2.
DT   27-MAR-2024, entry version 137.
DE   RecName: Full=Subtilisin inhibitor;
DE   AltName: Full=SSI type;
DE   Flags: Precursor;
GN   Name=ssi;
OS   Streptomyces albogriseolus.
OC   Bacteria; Actinomycetota; Actinomycetes; Kitasatosporales;
OC   Streptomycetaceae; Streptomyces; Streptomyces albogriseolus group.
OX   NCBI_TaxID=1887;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=S-3253;
RX   PubMed=2732212; DOI=10.1093/oxfordjournals.jbchem.a122670;
RA   Obata S., Taguchi S., Kumagai I., Miura K.;
RT   "Molecular cloning and nucleotide sequence determination of gene encoding
RT   Streptomyces subtilisin inhibitor (SSI).";
RL   J. Biochem. 105:367-371(1989).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Miura K., Kumagai I., Obata S., Kojima S., Taguchi S.;
RT   "Partial alteration of a protein Streptomyces subtilisin inhibitor by site-
RT   directed mutagenesis.";
RL   Proc. Jpn. Acad., B, Phys. Biol. Sci. 64:147-149(1988).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 32-144.
RC   STRAIN=S-3253;
RX   PubMed=2482228; DOI=10.1016/0378-1119(89)90501-5;
RA   Taguchi S., Nishiyama K., Kumagai I., Miura K.;
RT   "Analysis of transcriptional control regions in the Streptomyces
RT   subtilisin-inhibitor-encoding gene.";
RL   Gene 84:279-286(1989).
RN   [4]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 32-144.
RX   PubMed=8448204; DOI=10.1016/0167-4781(93)90212-v;
RA   Ueda Y., Taguchi S., Nishiyama K., Kumagai I., Miura K.;
RT   "Effect of a rare leucine codon, TTA, on expression of a foreign gene in
RT   Streptomyces lividans.";
RL   Biochim. Biophys. Acta 1172:262-266(1993).
RN   [5]
RP   PROTEIN SEQUENCE OF 32-144.
RC   STRAIN=S-3253;
RX   PubMed=4376147; DOI=10.1093/oxfordjournals.jbchem.a130672;
RA   Ikenaka T., Odani S., Sakai M., Nabeshima Y., Sato S., Murao S.;
RT   "Amino acid sequence of an alkaline proteinase inhibitor (Streptomyces
RT   subtilisin inhibitor) from Streptomyces albogriseolus S-3253.";
RL   J. Biochem. 76:1191-1209(1974).
RN   [6]
RP   SEQUENCE REVISION TO 142-143.
RX   PubMed=6993452; DOI=10.1093/oxfordjournals.jbchem.a132819;
RA   Sakai M., Odani S., Ikenaka T.;
RT   "Importance of the carboxyl-terminal four amino acid residues in the
RT   inhibitory activity of Streptomyces subtilisin inhibitor (with a revision
RT   of its carboxyl-terminal sequence).";
RL   J. Biochem. 87:891-898(1980).
RN   [7]
RP   X-RAY CRYSTALLOGRAPHY (2.6 ANGSTROMS).
RX   PubMed=763329; DOI=10.1038/277447a0;
RA   Mitsui Y., Satow Y., Watanabe Y., Hirono S., Iitaka Y.;
RT   "Crystal structures of Streptomyces subtilisin inhibitor and its complex
RT   with subtilisin BPN'.";
RL   Nature 277:447-452(1979).
RN   [8]
RP   X-RAY CRYSTALLOGRAPHY (2.6 ANGSTROMS).
RX   PubMed=6387152; DOI=10.1016/0022-2836(84)90150-5;
RA   Hirono S., Akagawa H., Mitsui Y., Iitaka Y.;
RT   "Crystal structure at 2.6-A resolution of the complex of subtilisin BPN'
RT   with streptomyces subtilisin inhibitor.";
RL   J. Mol. Biol. 178:389-413(1984).
RN   [9]
RP   MUTAGENESIS OF MET-104.
RX   PubMed=1366538; DOI=10.1038/nbt0590-449;
RA   Kojima S., Obata S., Kumagai I., Miura K.;
RT   "Alteration of the specificity of the Streptomyces subtilisin inhibitor by
RT   gene engineering.";
RL   Biotechnology (N.Y.) 8:449-452(1990).
RN   [10]
RP   MUTAGENESIS OF MET-104.
RX   PubMed=1908859; DOI=10.1093/oxfordjournals.jbchem.a123389;
RA   Kojima S., Nishiyama Y., Kumagai I., Miura K.;
RT   "Inhibition of subtilisin BPN' by reaction site P1 mutants of Streptomyces
RT   subtilisin inhibitor.";
RL   J. Biochem. 109:377-382(1991).
CC   -!- FUNCTION: Strong inhibitor of bacterial serine proteases such as
CC       subtilisin.
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; D00402; BAA00305.1; -; Genomic_DNA.
DR   EMBL; AH000937; AAA26821.1; -; Genomic_DNA.
DR   EMBL; AH000937; AAA26822.1; -; Genomic_DNA.
DR   EMBL; X73049; CAA51525.1; -; Genomic_DNA.
DR   EMBL; M54887; AAA26827.1; -; Genomic_DNA.
DR   PIR; JX0066; XSSMA.
DR   PDB; 2SIC; X-ray; 1.80 A; I=38-144.
DR   PDB; 2TLD; X-ray; 2.60 A; I=35-144.
DR   PDB; 3SIC; X-ray; 1.80 A; I=38-144.
DR   PDB; 3SSI; X-ray; 2.30 A; A=32-144.
DR   PDB; 5SIC; X-ray; 2.20 A; I=38-144.
DR   PDBsum; 2SIC; -.
DR   PDBsum; 2TLD; -.
DR   PDBsum; 3SIC; -.
DR   PDBsum; 3SSI; -.
DR   PDBsum; 5SIC; -.
DR   AlphaFoldDB; P01006; -.
DR   SMR; P01006; -.
DR   MINT; P01006; -.
DR   MEROPS; I16.003; -.
DR   EvolutionaryTrace; P01006; -.
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; Subtilisin inhibitor-like; 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; Subtilisin inhibitor; 1.
DR   PROSITE; PS00999; SSI; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Direct protein sequencing; Disulfide bond;
KW   Protease inhibitor; Repeat; Secreted; Serine protease inhibitor; Signal.
FT   SIGNAL          1..31
FT                   /evidence="ECO:0000269|PubMed:4376147"
FT   CHAIN           32..144
FT                   /note="Subtilisin inhibitor"
FT                   /id="PRO_0000033270"
FT   REPEAT          33..37
FT   REPEAT          39..43
FT   REGION          1..25
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   SITE            104..105
FT                   /note="Reactive bond for subtilisin"
FT   DISULFID        66..81
FT   DISULFID        102..132
FT   MUTAGEN         104
FT                   /note="M->D,E,V,I,G,P: Decrease in inhibition."
FT                   /evidence="ECO:0000269|PubMed:1366538,
FT                   ECO:0000269|PubMed:1908859"
FT   MUTAGEN         104
FT                   /note="M->K,R: Also inhibits trypsin."
FT                   /evidence="ECO:0000269|PubMed:1366538,
FT                   ECO:0000269|PubMed:1908859"
FT   MUTAGEN         104
FT                   /note="M->Y,W: Also inhibits chymotrypsin."
FT                   /evidence="ECO:0000269|PubMed:1366538,
FT                   ECO:0000269|PubMed:1908859"
FT   STRAND          42..52
FT                   /evidence="ECO:0007829|PDB:2SIC"
FT   TURN            53..55
FT                   /evidence="ECO:0007829|PDB:3SSI"
FT   STRAND          60..65
FT                   /evidence="ECO:0007829|PDB:2SIC"
FT   STRAND          67..69
FT                   /evidence="ECO:0007829|PDB:2SIC"
FT   STRAND          71..73
FT                   /evidence="ECO:0007829|PDB:2SIC"
FT   HELIX           77..87
FT                   /evidence="ECO:0007829|PDB:2SIC"
FT   HELIX           91..93
FT                   /evidence="ECO:0007829|PDB:3SSI"
FT   STRAND          98..103
FT                   /evidence="ECO:0007829|PDB:2SIC"
FT   STRAND          109..117
FT                   /evidence="ECO:0007829|PDB:2SIC"
FT   STRAND          120..130
FT                   /evidence="ECO:0007829|PDB:2SIC"
FT   HELIX           131..135
FT                   /evidence="ECO:0007829|PDB:2SIC"
FT   STRAND          138..140
FT                   /evidence="ECO:0007829|PDB:2SIC"
SQ   SEQUENCE   144 AA;  14312 MW;  BEA57AC7FDCD8004 CRC64;
     MRNTGAGPSP SVSRPPPSAA PLSGAALAAP GDAPSALYAP SALVLTVGKG VSATTAAPER
     AVTLTCAPGP SGTHPAAGSA CADLAAVGGD LNALTRGEDV MCPMVYDPVL LTVDGVWQGK
     RVSYERVFSN ECEMNAHGSS VFAF
//