ID   IAAB_HORVU              Reviewed;         149 AA.
AC   P32936;
DT   01-OCT-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1994, sequence version 2.
DT   02-SEP-2026, entry version 110.
DE   RecName: Full=Alpha-amylase/trypsin inhibitor CMb;
DE   AltName: Full=Chloroform/methanol-soluble protein CMb;
DE   Flags: Precursor;
GN   Name=IAT2;
OS   Hordeum vulgare (Barley).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; Liliopsida; Poales; Poaceae; BOP clade;
OC   Pooideae; Triticodae; Triticeae; Hordeinae; Hordeum.
OX   NCBI_TaxID=4513;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=cv. Abyssinian; TISSUE=Endosperm;
RX   PubMed=8219088; DOI=10.1007/bf00019301;
RA   Medina-Alcazar J., Hueros G., Carbonero P.;
RT   "Cloning of cDNA, expression, and chromosomal location of genes encoding
RT   the three types of subunits of the barley tetrameric inhibitor of insect
RT   alpha-amylase.";
RL   Plant Mol. Biol. 23:535-542(1993).
RN   [2]
RP   PROTEIN SEQUENCE OF 25-53.
RX   PubMed=3484638; DOI=10.1016/0167-4838(86)90318-3;
RA   Barber D., Sanchez-Monge R., Mendez E., Lazaro A., Garcia-Olmedo F.,
RA   Salcedo G.;
RT   "New alpha-amylase and trypsin inhibitors among the CM-proteins of barley
RT   (Hordeum vulgare).";
RL   Biochim. Biophys. Acta 869:115-118(1986).
RN   [3]
RP   PROTEIN SEQUENCE OF 25-33.
RC   STRAIN=cv. H354-295-2-5; TISSUE=Starchy endosperm;
RX   PubMed=8125056; DOI=10.1002/elps.11501401169;
RA   Flengsrud R.;
RT   "Separation of acidic barley endosperm proteins by two-dimensional
RT   electrophoresis.";
RL   Electrophoresis 14:1060-1066(1993).
CC   -!- FUNCTION: Part of a complex with inhibitory activity, but CMb is
CC       inactive as a separate subunit.
CC   -!- SUBUNIT: Heterotetramer of one CMa, one CMb and two CMd chains.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Endosperm.
CC   -!- PTM: Five disulfide bonds, which are essential for the inhibitor
CC       activity, are probably present. {ECO:0000305}.
CC   -!- PTM: Exists both in a glycosylated and in an unglycosylated form. The
CC       glycosylated form is a potent allergen.
CC   -!- ALLERGEN: Causes an allergic reaction in human. Involved in baker's
CC       asthma.
CC   -!- SIMILARITY: Belongs to the protease inhibitor I6 (cereal trypsin/alpha-
CC       amylase inhibitor) family. {ECO:0000305}.
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DR   EMBL; X69938; CAA49556.1; -; mRNA.
DR   PIR; S78524; S78524.
DR   AlphaFoldDB; P32936; -.
DR   SMR; P32936; -.
DR   Allergome; 418; Hor v 15.
DR   MEROPS; I06.004; -.
DR   GlyCosmos; P32936; 1 site, No reported glycans.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:InterPro.
DR   CDD; cd00261; AAI_SS; 1.
DR   Gene3D; 1.10.110.10; Plant lipid-transfer and hydrophobic proteins; 1.
DR   InterPro; IPR006106; Allergen/soft/tryp_amyl_inhib.
DR   InterPro; IPR006105; Allergen/tryp_amyl_inhib_CS.
DR   InterPro; IPR036312; Bifun_inhib/LTP/seed_sf.
DR   InterPro; IPR016140; Bifunc_inhib/LTP/seed_store.
DR   PANTHER; PTHR34481:SF7; ALPHA-AMYLASE_TRYPSIN INHIBITOR CM16; 1.
DR   PANTHER; PTHR34481; TRYPSIN/FACTOR XIIA INHIBITOR-RELATED; 1.
DR   Pfam; PF00234; Tryp_alpha_amyl; 1.
DR   PRINTS; PR00808; AMLASEINHBTR.
DR   SMART; SM00499; AAI; 1.
DR   SUPFAM; SSF47699; Bifunctional inhibitor/lipid-transfer protein/seed storage 2S albumin; 1.
DR   PROSITE; PS00426; CEREAL_TRYP_AMYL_INH; 1.
PE   1: Evidence at protein level;
KW   Allergen; Alpha-amylase inhibitor; Direct protein sequencing;
KW   Disulfide bond; Glycoprotein; Protease inhibitor; Secreted;
KW   Serine protease inhibitor; Signal.
FT   SIGNAL          1..24
FT                   /evidence="ECO:0000269|PubMed:3484638,
FT                   ECO:0000269|PubMed:8125056"
FT   CHAIN           25..149
FT                   /note="Alpha-amylase/trypsin inhibitor CMb"
FT                   /id="PRO_0000014351"
FT   CARBOHYD        124
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CONFLICT        30
FT                   /note="C -> D (in Ref. 3; AA sequence)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        33
FT                   /note="W -> P (in Ref. 3; AA sequence)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   149 AA;  16526 MW;  A33E42B146A42847 CRC64;
     MASKSSCDLL LAAVLVSIFA AVAAVGSEDC TPWTATPITP LPSCRDYVEQ QACRIETPGP
     PYLAKQQCCG ELANIPQQCR CQALRFFMGR KSRPDQSGLM ELPGCPREVQ MDFVRILVTP
     GFCNLTTVHN TPYCLAMDEW QWNRQFCSS
//