ID   SUIS_PIG                Reviewed;          62 AA.
AC   P56729;
DT   30-MAY-2000, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 2.
DT   02-DEC-2020, entry version 72.
DE   RecName: Full=Sucrase-isomaltase, intestinal;
DE   Contains:
DE     RecName: Full=Sucrase;
DE              EC=3.2.1.48;
DE   Contains:
DE     RecName: Full=Isomaltase;
DE              EC=3.2.1.10;
DE   Flags: Fragments;
GN   Name=SI;
OS   Sus scrofa (Pig).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Artiodactyla; Suina; Suidae; Sus.
OX   NCBI_TaxID=9823;
RN   [1]
RP   PROTEIN SEQUENCE OF 2-62.
RX   PubMed=7152027; DOI=10.1016/0014-5793(82)80833-8;
RA   Sjoestroem H., Noren O., Christiansen L.A., Wacker H., Spiess M.,
RA   Bigler-Meier B., Rickli E.E., Semenza G.;
RT   "N-terminal sequences of pig intestinal sucrase-isomaltase and pro-sucrase-
RT   isomaltase. Implications for the biosynthesis and membrane insertion of
RT   pro-sucrase-isomaltase.";
RL   FEBS Lett. 148:321-325(1982).
RN   [2]
RP   SULFATION.
RX   PubMed=3121301; DOI=10.1002/j.1460-2075.1987.tb02592.x;
RA   Danielsen E.M.;
RT   "Tyrosine sulfation, a post-translational modification of microvillar
RT   enzymes in the small intestinal enterocyte.";
RL   EMBO J. 6:2891-2896(1987).
CC   -!- FUNCTION: Plays an important role in the final stage of carbohydrate
CC       digestion. Isomaltase activity is specific for both alpha-1,4- and
CC       alpha-1,6-oligosaccharides (By similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of sucrose and maltose by an alpha-D-glucosidase-
CC         type action.; EC=3.2.1.48;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of (1->6)-alpha-D-glucosidic linkages in some
CC         oligosaccharides produced from starch and glycogen by alpha-amylase,
CC         and in isomaltose.; EC=3.2.1.10;
CC   -!- SUBUNIT: The resulting sucrase and isomaltase subunits stay associated
CC       with one another in a complex by non-covalent linkages.
CC   -!- SUBCELLULAR LOCATION: Apical cell membrane {ECO:0000250}; Single-pass
CC       type II membrane protein {ECO:0000250}. Note=Brush border.
CC       {ECO:0000250}.
CC   -!- PTM: The precursor is proteolytically cleaved when exposed to
CC       pancreatic proteases in the intestinal lumen.
CC   -!- PTM: Sulfated. {ECO:0000269|PubMed:3121301}.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 31 family. {ECO:0000305}.
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DR   PIR; A25987; A25987.
DR   PeptideAtlas; P56729; -.
DR   Proteomes; UP000008227; Unplaced.
DR   Proteomes; UP000314985; Unplaced.
DR   GO; GO:0016324; C:apical plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0004574; F:oligo-1,6-glucosidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0004575; F:sucrose alpha-glucosidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0008152; P:metabolic process; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Cell membrane; Direct protein sequencing; Glycosidase; Hydrolase; Membrane;
KW   Multifunctional enzyme; Phosphoprotein; Reference proteome; Repeat;
KW   Signal-anchor; Sulfation; Transmembrane; Transmembrane helix.
FT   INIT_MET        1
FT                   /note="Removed"
FT                   /evidence="ECO:0000269|PubMed:7152027"
FT   CHAIN           2..>38
FT                   /note="Isomaltase"
FT                   /id="PRO_0000018554"
FT   CHAIN           39..>62
FT                   /note="Sucrase"
FT                   /id="PRO_0000018555"
FT   TOPO_DOM        2..12
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        13..32
FT                   /note="Helical; Signal-anchor for type II membrane protein"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        33..>38
FT                   /note="Lumenal"
FT                   /evidence="ECO:0000255"
FT   MOD_RES         7
FT                   /note="Phosphoserine; by PKA"
FT                   /evidence="ECO:0000250|UniProtKB:P14410"
FT   MOD_RES         59
FT                   /note="Sulfotyrosine"
FT                   /evidence="ECO:0000255"
FT   UNSURE          33
FT   UNSURE          34
FT   UNSURE          51
FT                   /note="M or V"
FT   UNSURE          53
FT                   /note="M or V"
FT   UNSURE          54
FT                   /note="T or K"
FT   UNSURE          57
FT                   /note="T or K"
FT   UNSURE          60
FT                   /note="M or V"
FT   NON_CONS        38..39
FT                   /evidence="ECO:0000305"
FT   NON_TER         62
SQ   SEQUENCE   62 AA;  6893 MW;  7D4E3C6AFC5AFB8B CRC64;
     MARKKFSGLE IXLIVLFAIV LSIAIALVVV XASKXPAVIK LPSDPIPTLR MEMTYHTDYM
     LE