ID   SUIS_RAT                Reviewed;        1841 AA.
AC   P23739;
DT   01-NOV-1991, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 5.
DT   27-MAR-2024, entry version 169.
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;
GN   Name=Si;
OS   Rattus norvegicus (Rat).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae;
OC   Murinae; Rattus.
OX   NCBI_TaxID=10116;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=Sprague-Dawley; TISSUE=Intestine;
RX   PubMed=7821806; DOI=10.1016/0378-1119(94)90452-9;
RA   Chandrasena G., Osterholm D.E., Sunitha I., Henning S.J.;
RT   "Cloning and sequencing of a full-length rat sucrase-isomaltase-encoding
RT   cDNA.";
RL   Gene 150:355-360(1994).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA] OF 87-362.
RC   STRAIN=Fischer 344; TISSUE=Intestine;
RX   PubMed=2268340; DOI=10.1016/s0006-291x(05)80853-8;
RA   Traber P.G.;
RT   "Regulation of sucrase-isomaltase gene expression along the crypt-villus
RT   axis of rat small intestine.";
RL   Biochem. Biophys. Res. Commun. 173:765-773(1990).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [MRNA] OF 733-1373.
RC   STRAIN=Sprague-Dawley; TISSUE=Duodenum;
RX   PubMed=2400788; DOI=10.1016/0167-4781(90)90121-h;
RA   Broyart J.-P., Hugot J.-P., Perret C., Porteu A.;
RT   "Molecular cloning and characterization of a rat intestinal sucrase-
RT   isomaltase cDNA. Regulation of sucrase-isomaltase gene expression by
RT   sucrose feeding.";
RL   Biochim. Biophys. Acta 1087:61-67(1990).
RN   [4]
RP   PROTEIN SEQUENCE OF N-TERMINUS OF ISOMALTASE AND SUCRASE.
RX   PubMed=6802834; DOI=10.1016/s0021-9258(18)34754-9;
RA   Hauri H.-P., Wacker H., Rickli E.E., Bigler-Meier B., Quaroni A.,
RA   Semenza G.;
RT   "Biosynthesis of sucrase-isomaltase. Purification and NH2-terminal amino
RT   acid sequence of the rat sucrase-isomaltase precursor (pro-sucrase-
RT   isomaltase) from fetal intestinal transplants.";
RL   J. Biol. Chem. 257:4522-4528(1982).
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.
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; Single-pass type II
CC       membrane protein. Note=Brush border.
CC   -!- PTM: The precursor is proteolytically cleaved when exposed to
CC       pancreatic proteases in the intestinal lumen.
CC   -!- PTM: Sulfated. {ECO:0000250}.
CC   -!- MISCELLANEOUS: There is a high degree of homology between the
CC       isomaltase and sucrase portions (41% of amino acid identity) indicating
CC       that this protein is evolved by partial gene duplication.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 31 family. {ECO:0000305}.
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DR   EMBL; L25926; AAA65097.1; -; mRNA.
DR   EMBL; M62889; AAA42144.1; -; mRNA.
DR   EMBL; X15546; CAA33552.1; -; mRNA.
DR   PIR; S11386; S11386.
DR   PIR; T10799; T10799.
DR   RefSeq; NP_037193.1; NM_013061.1.
DR   AlphaFoldDB; P23739; -.
DR   SMR; P23739; -.
DR   STRING; 10116.ENSRNOP00000045106; -.
DR   BindingDB; P23739; -.
DR   ChEMBL; CHEMBL3114; -.
DR   DrugCentral; P23739; -.
DR   CAZy; GH31; Glycoside Hydrolase Family 31.
DR   GlyCosmos; P23739; 16 sites, No reported glycans.
DR   GlyGen; P23739; 16 sites.
DR   iPTMnet; P23739; -.
DR   PhosphoSitePlus; P23739; -.
DR   PaxDb; 10116-ENSRNOP00000045106; -.
DR   UCSC; RGD:3675; rat.
DR   AGR; RGD:3675; -.
DR   RGD; 3675; Si.
DR   eggNOG; KOG1065; Eukaryota.
DR   InParanoid; P23739; -.
DR   OrthoDB; 5480935at2759; -.
DR   PhylomeDB; P23739; -.
DR   BRENDA; 3.2.1.10; 5301.
DR   Reactome; R-RNO-189085; Digestion of dietary carbohydrate.
DR   SABIO-RK; P23739; -.
DR   PRO; PR:P23739; -.
DR   Proteomes; UP000002494; Unplaced.
DR   GO; GO:0016324; C:apical plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0005903; C:brush border; IDA:RGD.
DR   GO; GO:0016020; C:membrane; ISO:RGD.
DR   GO; GO:0004558; F:alpha-1,4-glucosidase activity; IBA:GO_Central.
DR   GO; GO:0004564; F:beta-fructofuranosidase activity; IDA:RGD.
DR   GO; GO:0030246; F:carbohydrate binding; IEA:InterPro.
DR   GO; GO:0004574; F:oligo-1,6-glucosidase activity; IDA:RGD.
DR   GO; GO:0004575; F:sucrose alpha-glucosidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0009750; P:response to fructose; IEP:RGD.
DR   GO; GO:0051384; P:response to glucocorticoid; IEP:RGD.
DR   GO; GO:0032868; P:response to insulin; IEP:RGD.
DR   GO; GO:0007584; P:response to nutrient; IEP:RGD.
DR   GO; GO:0042594; P:response to starvation; IEP:RGD.
DR   GO; GO:0009744; P:response to sucrose; IEP:RGD.
DR   GO; GO:0033189; P:response to vitamin A; IEP:RGD.
DR   GO; GO:0005987; P:sucrose catabolic process; ISO:RGD.
DR   CDD; cd06602; GH31_MGAM_SI_GAA; 2.
DR   CDD; cd14752; GH31_N; 2.
DR   CDD; cd00111; Trefoil; 2.
DR   Gene3D; 3.20.20.80; Glycosidases; 2.
DR   Gene3D; 2.60.40.1760; glycosyl hydrolase (family 31); 2.
DR   Gene3D; 2.60.40.1180; Golgi alpha-mannosidase II; 4.
DR   Gene3D; 4.10.110.10; Spasmolytic Protein, domain 1; 2.
DR   InterPro; IPR011013; Gal_mutarotase_sf_dom.
DR   InterPro; IPR030458; Glyco_hydro_31_AS.
DR   InterPro; IPR048395; Glyco_hydro_31_C.
DR   InterPro; IPR030459; Glyco_hydro_31_CS.
DR   InterPro; IPR025887; Glyco_hydro_31_N_dom.
DR   InterPro; IPR000322; Glyco_hydro_31_TIM.
DR   InterPro; IPR013780; Glyco_hydro_b.
DR   InterPro; IPR017853; Glycoside_hydrolase_SF.
DR   InterPro; IPR017957; P_trefoil_CS.
DR   InterPro; IPR000519; P_trefoil_dom.
DR   InterPro; IPR044913; P_trefoil_dom_sf.
DR   PANTHER; PTHR22762; ALPHA-GLUCOSIDASE; 1.
DR   PANTHER; PTHR22762:SF168; P-TYPE DOMAIN-CONTAINING PROTEIN; 1.
DR   Pfam; PF13802; Gal_mutarotas_2; 2.
DR   Pfam; PF01055; Glyco_hydro_31_2nd; 2.
DR   Pfam; PF21365; Glyco_hydro_31_3rd; 2.
DR   Pfam; PF00088; Trefoil; 2.
DR   SMART; SM00018; PD; 2.
DR   SUPFAM; SSF51445; (Trans)glycosidases; 2.
DR   SUPFAM; SSF74650; Galactose mutarotase-like; 2.
DR   SUPFAM; SSF51011; Glycosyl hydrolase domain; 2.
DR   SUPFAM; SSF57492; Trefoil; 1.
DR   PROSITE; PS00129; GLYCOSYL_HYDROL_F31_1; 2.
DR   PROSITE; PS00707; GLYCOSYL_HYDROL_F31_2; 1.
DR   PROSITE; PS00025; P_TREFOIL_1; 1.
DR   PROSITE; PS51448; P_TREFOIL_2; 2.
PE   1: Evidence at protein level;
KW   Cell membrane; Direct protein sequencing; Disulfide bond; Glycoprotein;
KW   Glycosidase; Hydrolase; Membrane; Multifunctional enzyme; Phosphoprotein;
KW   Reference proteome; Repeat; Signal-anchor; Sulfation; Transmembrane;
KW   Transmembrane helix.
FT   CHAIN           1..1841
FT                   /note="Sucrase-isomaltase, intestinal"
FT                   /id="PRO_0000018559"
FT   CHAIN           1..1013
FT                   /note="Isomaltase"
FT                   /id="PRO_0000018560"
FT   CHAIN           1014..1841
FT                   /note="Sucrase"
FT                   /id="PRO_0000018561"
FT   TOPO_DOM        1..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..1841
FT                   /note="Lumenal"
FT                   /evidence="ECO:0000255"
FT   DOMAIN          71..120
FT                   /note="P-type 1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00779"
FT   DOMAIN          936..984
FT                   /note="P-type 2"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00779"
FT   REGION          42..81
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          120..1013
FT                   /note="Isomaltase"
FT   REGION          1014..1841
FT                   /note="Sucrase"
FT   COMPBIAS        42..72
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        514
FT                   /note="Nucleophile; for isomaltase activity"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10066"
FT   ACT_SITE        615
FT                   /note="For isomaltase activity"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        1399
FT                   /note="Nucleophile; for sucrase activity"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10066"
FT   ACT_SITE        1402
FT                   /note="For sucrase activity"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        1512
FT                   /note="Proton donor; for sucrase activity"
FT                   /evidence="ECO:0000250"
FT   BINDING         274
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         398
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         599
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         673
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         7
FT                   /note="Phosphoserine; by PKA"
FT                   /evidence="ECO:0000250|UniProtKB:P14410"
FT   MOD_RES         401
FT                   /note="Sulfotyrosine"
FT                   /evidence="ECO:0000255"
FT   MOD_RES         410
FT                   /note="Sulfotyrosine"
FT                   /evidence="ECO:0000255"
FT   MOD_RES         1387
FT                   /note="Sulfotyrosine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        109
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        464
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        758
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        765
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        867
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        910
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1240
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1308
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1345
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1359
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1373
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1485
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1513
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1575
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1762
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1829
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   DISULFID        73..104
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00779"
FT   DISULFID        87..103
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00779"
FT   DISULFID        98..116
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00779"
FT   DISULFID        646..657
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00779"
FT   CONFLICT        87
FT                   /note="C -> W (in Ref. 1; AAA65097)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        92
FT                   /note="H -> S (in Ref. 2; AAA42144)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        95
FT                   /note="K -> Q (in Ref. 2; AAA42144)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        736
FT                   /note="E -> V (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        842
FT                   /note="E -> Q (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        916
FT                   /note="A -> T (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        924
FT                   /note="A -> R (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        930..931
FT                   /note="AG -> GT (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        938..939
FT                   /note="CR -> SQ (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        959..962
FT                   /note="GTCT -> ETDK (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        980
FT                   /note="Y -> C (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        986
FT                   /note="N -> H (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        997..998
FT                   /note="LP -> SL (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        1010
FT                   /note="P -> A (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        1023
FT                   /note="T -> P (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        1027
FT                   /note="G -> E (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        1032
FT                   /note="P -> K (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        1094
FT                   /note="R -> S (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        1099
FT                   /note="G -> A (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        1302
FT                   /note="A -> D (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        1337..1340
FT                   /note="PKVW -> AKWG (in Ref. 3; CAA33552)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   1841 AA;  210350 MW;  E186B8632475EE09 CRC64;
     MAKKKFSALE ISLIVLFIIV TAIAIALVTV LATKVPAVEE IKSPTPTSNS TPTSTPTSTS
     TPTSTSTPSP GKCPPEQGEP INERINCIPE QHPTKAICEE RGCCWRPWNN TVIPWCFFAD
     NHGYNAESIT NENAGLKATL NRIPSPTLFG EDIKSVILTT QTQTGNRFRF KITDPNNKRY
     EVPHQFVKEE TGIPAADTLY DVQVSENPFS IKVIRKSNNK VLCDTSVGPL LYSNQYLQIS
     TRLPSEYIYG FGGHIHKRFR HDLYWKTWPI FTRDEIPGDN NHNLYGHQTF FMGIGDTSGK
     SYGVFLMNSN AMEVFIQPTP IITYRVTGGI LDFYIFLGDT PEQVVQQYQE VHWRPAMPAY
     WNLGFQLSRW NYGSLDTVSE VVRRNREAGI PYDAQVTDID YMEDHKEFTY DRVKFNGLPE
     FAQDLHNHGK YIIILDPAIS INKRANGAEY QTYVRGNEKN VWVNESDGTT PLIGEVWPGL
     TVYPDFTNPQ TIEWWANECN LFHQQVEYDG LWIDMNEVSS FIQGSLNLKG VLLIVLNYPP
     FTPGILDKVM YSKTLCMDAV QHWGKQYDVH SLYGYSMAIA TEQAVERVFP NKRSFILTRS
     TFGGSGRHAN HWLGDNTASW EQMEWSITGM LEFGIFGMPL VGATSCGFLA DTTEELCRRW
     MQLGAFYPFS RNHNAEGYME QDPAYFGQDS SRHYLTIRYT LLPFLYTLFY RAHMFGETVA
     RPFLYEFYDD TNSWIEDTQF LWGPALLITP VLRPGVENVS AYIPNATWYD YETGIKRPWR
     KERINMYLPG DKIGLHLRGG YIIPTQEPDV TTTASRKNPL GLIVALDDNQ AAKGELFWDD
     GESKDSIEKK MYILYTFSVS NNELVLNCTH SSYAEGTSLA FKTIKVLGLR EDVRSITVGE
     NDQQMATHTN FTFDSANKIL SITALNFNLA GSFIVRWCRT FSDNEKFTCY PDVGTATEGT
     CTQRGCLWQP VSGLSNVPPY YFPPENNPYT LTSIQPLPTG ITAELQLNPP NARIKLPSNP
     ISTLRVGVKY HPNDMLQFKI YDAQHKRYEV PVPLNIPDTP TSSNERLYDV EIKENPFGIQ
     VRRRSSGKLI WDSRLPGFGF NDQFIQISTR LPSNYLYGFG EVEHTAFKRD LNWHTWGMFT
     RDQPPGYKLN SYGFHPYYMA LENEGNAHGV LLLNSNGMDV TFQPTPALTY RTIGGILDFY
     MFLGPTPEIA TRQYHEVIGF PVMPPYWALG FQLCRYGYRN TSEIEQLYND MVAANIPYDV
     QYTDINYMER QLDFTIGERF KTLPEFVDRI RKDGMKYIVI LAPAISGNET QPYPAFERGI
     QKDVFVKWPN TNDICWPKVW PDLPNVTIDE TITEDEAVNA SRAHVAFPDF FRNSTLEWWA
     REIYDFYNEK MKFDGLWIDM NEPSSFGIQM GGKVLNECRR MMTLNYPPVF SPELRVKEGE
     GASISEAMCM ETEHILIDGS SVLQYDVHNL YGWSQVKPTL DALQNTTGLR GIVISRSTYP
     TTGRWGGHWL GDNYTTWDNL EKSLIGMLEL NLFGIPYIGA DICGVFHDSG YPSLYFVGIQ
     VGAFYPYPRE SPTINFTRSQ DPVSWMKLLL QMSKKVLEIR YTLLPYFYTQ MHEAHAHGGT
     VIRPLMHEFF DDKETWEIYK QFLWGPAFMV TPVVEPFRTS VTGYVPKARW FDYHTGADIK
     LKGILHTFSA PFDTINLHVR GGYILPCQEP ARNTHLSRQN YMKLIVAADD NQMAQGTLFG
     DDGESIDTYE RGQYTSIQFN LNQTTLTSTV LANGYKNKQE MRLGSIHIWG KGTLRISNAN
     LVYGGRKHQP PFTQEEAKET LIFDLKNMNV TLDEPIQITW S
//