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Protein

Sucrase-isomaltase, intestinal

Gene

Si

Organism
Rattus norvegicus (Rat)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Plays an important role in the final stage of carbohydrate digestion. Isomaltase activity is specific for both alpha-1,4- and alpha-1,6-oligosaccharides.

Catalytic activityi

Hydrolysis of sucrose and maltose by an alpha-D-glucosidase-type action.
Hydrolysis of (1->6)-alpha-D-glucosidic linkages in some oligosaccharides produced from starch and glycogen by alpha-amylase, and in isomaltose.

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Binding sitei274 – 2741SubstrateBy similarity
Binding sitei398 – 3981SubstrateBy similarity
Active sitei514 – 5141Nucleophile; for isomaltase activityPROSITE-ProRule annotation
Binding sitei599 – 5991SubstrateBy similarity
Active sitei615 – 6151For isomaltase activityBy similarity
Binding sitei673 – 6731SubstrateBy similarity
Active sitei1399 – 13991Nucleophile; for sucrase activityPROSITE-ProRule annotation
Active sitei1402 – 14021For sucrase activityBy similarity
Active sitei1512 – 15121Proton donor; for sucrase activityBy similarity

GO - Molecular functioni

  • beta-fructofuranosidase activity Source: RGD
  • carbohydrate binding Source: InterPro
  • oligo-1,6-glucosidase activity Source: RGD
  • sucrose alpha-glucosidase activity Source: UniProtKB-EC

GO - Biological processi

  • aging Source: RGD
  • carbohydrate metabolic process Source: InterPro
  • response to fructose Source: RGD
  • response to glucocorticoid Source: RGD
  • response to insulin Source: RGD
  • response to nutrient Source: RGD
  • response to starvation Source: RGD
  • response to sucrose Source: RGD
  • response to vitamin A Source: RGD
Complete GO annotation...

Keywords - Molecular functioni

Glycosidase, Hydrolase

Enzyme and pathway databases

BRENDAi3.2.1.10. 5301.
SABIO-RKP23739.

Protein family/group databases

CAZyiGH31. Glycoside Hydrolase Family 31.

Names & Taxonomyi

Protein namesi
Recommended name:
Sucrase-isomaltase, intestinal
Cleaved into the following 2 chains:
Gene namesi
Name:Si
OrganismiRattus norvegicus (Rat)
Taxonomic identifieri10116 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeRattus
ProteomesiUP000002494 Componenti: Unplaced

Organism-specific databases

RGDi3675. Si.

Subcellular locationi

Topology

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Topological domaini2 – 1211CytoplasmicSequence AnalysisAdd
BLAST
Transmembranei13 – 3220Helical; Signal-anchor for type II membrane proteinSequence AnalysisAdd
BLAST
Topological domaini33 – 18411809LumenalSequence AnalysisAdd
BLAST

GO - Cellular componenti

  • apical plasma membrane Source: UniProtKB-SubCell
  • brush border Source: RGD
  • integral component of membrane Source: UniProtKB-KW
  • membrane raft Source: RGD
Complete GO annotation...

Keywords - Cellular componenti

Cell membrane, Membrane

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Initiator methioninei1 – 11RemovedBy similarity
Chaini2 – 18411840Sucrase-isomaltase, intestinalPRO_0000018559Add
BLAST
Chaini2 – 10131012IsomaltasePRO_0000018560Add
BLAST
Chaini1014 – 1841828SucrasePRO_0000018561Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei7 – 71Phosphoserine; by PKABy similarity
Disulfide bondi73 ↔ 104PROSITE-ProRule annotation
Disulfide bondi87 ↔ 103PROSITE-ProRule annotation
Disulfide bondi98 ↔ 116PROSITE-ProRule annotation
Glycosylationi109 – 1091N-linked (GlcNAc...)Sequence Analysis
Modified residuei401 – 4011SulfotyrosineSequence Analysis
Modified residuei410 – 4101SulfotyrosineSequence Analysis
Glycosylationi464 – 4641N-linked (GlcNAc...)Sequence Analysis
Disulfide bondi646 ↔ 657PROSITE-ProRule annotation
Glycosylationi758 – 7581N-linked (GlcNAc...)Sequence Analysis
Glycosylationi765 – 7651N-linked (GlcNAc...)Sequence Analysis
Glycosylationi867 – 8671N-linked (GlcNAc...)Sequence Analysis
Glycosylationi910 – 9101N-linked (GlcNAc...)Sequence Analysis
Glycosylationi1240 – 12401N-linked (GlcNAc...)Sequence Analysis
Glycosylationi1308 – 13081N-linked (GlcNAc...)Sequence Analysis
Glycosylationi1345 – 13451N-linked (GlcNAc...)Sequence Analysis
Glycosylationi1359 – 13591N-linked (GlcNAc...)Sequence Analysis
Glycosylationi1373 – 13731N-linked (GlcNAc...)Sequence Analysis
Modified residuei1387 – 13871SulfotyrosineSequence Analysis
Glycosylationi1485 – 14851N-linked (GlcNAc...)Sequence Analysis
Glycosylationi1513 – 15131N-linked (GlcNAc...)Sequence Analysis
Glycosylationi1575 – 15751N-linked (GlcNAc...)Sequence Analysis
Glycosylationi1762 – 17621N-linked (GlcNAc...)Sequence Analysis
Glycosylationi1829 – 18291N-linked (GlcNAc...)Sequence Analysis

Post-translational modificationi

The precursor is proteolytically cleaved when exposed to pancreatic proteases in the intestinal lumen.
Sulfated.By similarity

Keywords - PTMi

Disulfide bond, Glycoprotein, Phosphoprotein, Sulfation

Proteomic databases

PRIDEiP23739.

PTM databases

PhosphoSiteiP23739.

Expressioni

Gene expression databases

GenevisibleiP23739. RN.

Interactioni

Subunit structurei

The resulting sucrase and isomaltase subunits stay associated with one another in a complex by non-covalent linkages.

Structurei

3D structure databases

ProteinModelPortaliP23739.
SMRiP23739. Positions 83-937.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini71 – 12050P-type 1PROSITE-ProRule annotationAdd
BLAST
Domaini936 – 98449P-type 2PROSITE-ProRule annotationAdd
BLAST

Region

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Regioni120 – 1013894IsomaltaseAdd
BLAST
Regioni1014 – 1841828SucraseAdd
BLAST

Compositional bias

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Compositional biasi43 – 7028Ser/Thr-richAdd
BLAST

Sequence similaritiesi

Belongs to the glycosyl hydrolase 31 family.Curated
Contains 2 P-type (trefoil) domains.PROSITE-ProRule annotation

Keywords - Domaini

Repeat, Signal-anchor, Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiCOG1501.
HOGENOMiHOG000067936.
HOVERGENiHBG080721.
InParanoidiP23739.
KOiK01203.
PhylomeDBiP23739.

Family and domain databases

Gene3Di4.10.110.10. 1 hit.
InterProiIPR011013. Gal_mutarotase_SF_dom.
IPR000322. Glyco_hydro_31.
IPR030458. Glyco_hydro_31_AS.
IPR030459. Glyco_hydro_31_CS.
IPR017853. Glycoside_hydrolase_SF.
IPR000519. P_trefoil.
IPR017957. P_trefoil_CS.
[Graphical view]
PfamiPF01055. Glyco_hydro_31. 2 hits.
PF00088. Trefoil. 1 hit.
[Graphical view]
SMARTiSM00018. PD. 2 hits.
[Graphical view]
SUPFAMiSSF51445. SSF51445. 4 hits.
SSF57492. SSF57492. 1 hit.
SSF74650. SSF74650. 2 hits.
PROSITEiPS00129. GLYCOSYL_HYDROL_F31_1. 2 hits.
PS00707. GLYCOSYL_HYDROL_F31_2. 1 hit.
PS00025. P_TREFOIL_1. 1 hit.
PS51448. P_TREFOIL_2. 2 hits.
[Graphical view]

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P23739-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MAKKKFSALE ISLIVLFIIV TAIAIALVTV LATKVPAVEE IKSPTPTSNS
60 70 80 90 100
TPTSTPTSTS TPTSTSTPSP GKCPPEQGEP INERINCIPE QHPTKAICEE
110 120 130 140 150
RGCCWRPWNN TVIPWCFFAD NHGYNAESIT NENAGLKATL NRIPSPTLFG
160 170 180 190 200
EDIKSVILTT QTQTGNRFRF KITDPNNKRY EVPHQFVKEE TGIPAADTLY
210 220 230 240 250
DVQVSENPFS IKVIRKSNNK VLCDTSVGPL LYSNQYLQIS TRLPSEYIYG
260 270 280 290 300
FGGHIHKRFR HDLYWKTWPI FTRDEIPGDN NHNLYGHQTF FMGIGDTSGK
310 320 330 340 350
SYGVFLMNSN AMEVFIQPTP IITYRVTGGI LDFYIFLGDT PEQVVQQYQE
360 370 380 390 400
VHWRPAMPAY WNLGFQLSRW NYGSLDTVSE VVRRNREAGI PYDAQVTDID
410 420 430 440 450
YMEDHKEFTY DRVKFNGLPE FAQDLHNHGK YIIILDPAIS INKRANGAEY
460 470 480 490 500
QTYVRGNEKN VWVNESDGTT PLIGEVWPGL TVYPDFTNPQ TIEWWANECN
510 520 530 540 550
LFHQQVEYDG LWIDMNEVSS FIQGSLNLKG VLLIVLNYPP FTPGILDKVM
560 570 580 590 600
YSKTLCMDAV QHWGKQYDVH SLYGYSMAIA TEQAVERVFP NKRSFILTRS
610 620 630 640 650
TFGGSGRHAN HWLGDNTASW EQMEWSITGM LEFGIFGMPL VGATSCGFLA
660 670 680 690 700
DTTEELCRRW MQLGAFYPFS RNHNAEGYME QDPAYFGQDS SRHYLTIRYT
710 720 730 740 750
LLPFLYTLFY RAHMFGETVA RPFLYEFYDD TNSWIEDTQF LWGPALLITP
760 770 780 790 800
VLRPGVENVS AYIPNATWYD YETGIKRPWR KERINMYLPG DKIGLHLRGG
810 820 830 840 850
YIIPTQEPDV TTTASRKNPL GLIVALDDNQ AAKGELFWDD GESKDSIEKK
860 870 880 890 900
MYILYTFSVS NNELVLNCTH SSYAEGTSLA FKTIKVLGLR EDVRSITVGE
910 920 930 940 950
NDQQMATHTN FTFDSANKIL SITALNFNLA GSFIVRWCRT FSDNEKFTCY
960 970 980 990 1000
PDVGTATEGT CTQRGCLWQP VSGLSNVPPY YFPPENNPYT LTSIQPLPTG
1010 1020 1030 1040 1050
ITAELQLNPP NARIKLPSNP ISTLRVGVKY HPNDMLQFKI YDAQHKRYEV
1060 1070 1080 1090 1100
PVPLNIPDTP TSSNERLYDV EIKENPFGIQ VRRRSSGKLI WDSRLPGFGF
1110 1120 1130 1140 1150
NDQFIQISTR LPSNYLYGFG EVEHTAFKRD LNWHTWGMFT RDQPPGYKLN
1160 1170 1180 1190 1200
SYGFHPYYMA LENEGNAHGV LLLNSNGMDV TFQPTPALTY RTIGGILDFY
1210 1220 1230 1240 1250
MFLGPTPEIA TRQYHEVIGF PVMPPYWALG FQLCRYGYRN TSEIEQLYND
1260 1270 1280 1290 1300
MVAANIPYDV QYTDINYMER QLDFTIGERF KTLPEFVDRI RKDGMKYIVI
1310 1320 1330 1340 1350
LAPAISGNET QPYPAFERGI QKDVFVKWPN TNDICWPKVW PDLPNVTIDE
1360 1370 1380 1390 1400
TITEDEAVNA SRAHVAFPDF FRNSTLEWWA REIYDFYNEK MKFDGLWIDM
1410 1420 1430 1440 1450
NEPSSFGIQM GGKVLNECRR MMTLNYPPVF SPELRVKEGE GASISEAMCM
1460 1470 1480 1490 1500
ETEHILIDGS SVLQYDVHNL YGWSQVKPTL DALQNTTGLR GIVISRSTYP
1510 1520 1530 1540 1550
TTGRWGGHWL GDNYTTWDNL EKSLIGMLEL NLFGIPYIGA DICGVFHDSG
1560 1570 1580 1590 1600
YPSLYFVGIQ VGAFYPYPRE SPTINFTRSQ DPVSWMKLLL QMSKKVLEIR
1610 1620 1630 1640 1650
YTLLPYFYTQ MHEAHAHGGT VIRPLMHEFF DDKETWEIYK QFLWGPAFMV
1660 1670 1680 1690 1700
TPVVEPFRTS VTGYVPKARW FDYHTGADIK LKGILHTFSA PFDTINLHVR
1710 1720 1730 1740 1750
GGYILPCQEP ARNTHLSRQN YMKLIVAADD NQMAQGTLFG DDGESIDTYE
1760 1770 1780 1790 1800
RGQYTSIQFN LNQTTLTSTV LANGYKNKQE MRLGSIHIWG KGTLRISNAN
1810 1820 1830 1840
LVYGGRKHQP PFTQEEAKET LIFDLKNMNV TLDEPIQITW S
Length:1,841
Mass (Da):210,350
Last modified:January 23, 2007 - v5
Checksum:iE186B8632475EE09
GO

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti87 – 871C → W in AAA65097 (PubMed:7821806).Curated
Sequence conflicti92 – 921H → S in AAA42144 (PubMed:2268340).Curated
Sequence conflicti95 – 951K → Q in AAA42144 (PubMed:2268340).Curated
Sequence conflicti736 – 7361E → V in CAA33552 (PubMed:2400788).Curated
Sequence conflicti842 – 8421E → Q in CAA33552 (PubMed:2400788).Curated
Sequence conflicti916 – 9161A → T in CAA33552 (PubMed:2400788).Curated
Sequence conflicti924 – 9241A → R in CAA33552 (PubMed:2400788).Curated
Sequence conflicti930 – 9312AG → GT in CAA33552 (PubMed:2400788).Curated
Sequence conflicti938 – 9392CR → SQ in CAA33552 (PubMed:2400788).Curated
Sequence conflicti959 – 9624GTCT → ETDK in CAA33552 (PubMed:2400788).Curated
Sequence conflicti980 – 9801Y → C in CAA33552 (PubMed:2400788).Curated
Sequence conflicti986 – 9861N → H in CAA33552 (PubMed:2400788).Curated
Sequence conflicti997 – 9982LP → SL in CAA33552 (PubMed:2400788).Curated
Sequence conflicti1010 – 10101P → A in CAA33552 (PubMed:2400788).Curated
Sequence conflicti1023 – 10231T → P in CAA33552 (PubMed:2400788).Curated
Sequence conflicti1027 – 10271G → E in CAA33552 (PubMed:2400788).Curated
Sequence conflicti1032 – 10321P → K in CAA33552 (PubMed:2400788).Curated
Sequence conflicti1094 – 10941R → S in CAA33552 (PubMed:2400788).Curated
Sequence conflicti1099 – 10991G → A in CAA33552 (PubMed:2400788).Curated
Sequence conflicti1302 – 13021A → D in CAA33552 (PubMed:2400788).Curated
Sequence conflicti1337 – 13404PKVW → AKWG in CAA33552 (PubMed:2400788).Curated

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
L25926 mRNA. Translation: AAA65097.1.
M62889 mRNA. Translation: AAA42144.1.
X15546 mRNA. Translation: CAA33552.1.
PIRiS11386.
T10799.
RefSeqiNP_037193.1. NM_013061.1.
UniGeneiRn.10057.

Genome annotation databases

GeneIDi497756.
KEGGirno:497756.
UCSCiRGD:3675. rat.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
L25926 mRNA. Translation: AAA65097.1.
M62889 mRNA. Translation: AAA42144.1.
X15546 mRNA. Translation: CAA33552.1.
PIRiS11386.
T10799.
RefSeqiNP_037193.1. NM_013061.1.
UniGeneiRn.10057.

3D structure databases

ProteinModelPortaliP23739.
SMRiP23739. Positions 83-937.
ModBaseiSearch...
MobiDBiSearch...

Chemistry

BindingDBiP23739.
ChEMBLiCHEMBL3114.

Protein family/group databases

CAZyiGH31. Glycoside Hydrolase Family 31.

PTM databases

PhosphoSiteiP23739.

Proteomic databases

PRIDEiP23739.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

GeneIDi497756.
KEGGirno:497756.
UCSCiRGD:3675. rat.

Organism-specific databases

CTDi6476.
RGDi3675. Si.

Phylogenomic databases

eggNOGiCOG1501.
HOGENOMiHOG000067936.
HOVERGENiHBG080721.
InParanoidiP23739.
KOiK01203.
PhylomeDBiP23739.

Enzyme and pathway databases

BRENDAi3.2.1.10. 5301.
SABIO-RKP23739.

Miscellaneous databases

NextBioi697744.
PROiP23739.

Gene expression databases

GenevisibleiP23739. RN.

Family and domain databases

Gene3Di4.10.110.10. 1 hit.
InterProiIPR011013. Gal_mutarotase_SF_dom.
IPR000322. Glyco_hydro_31.
IPR030458. Glyco_hydro_31_AS.
IPR030459. Glyco_hydro_31_CS.
IPR017853. Glycoside_hydrolase_SF.
IPR000519. P_trefoil.
IPR017957. P_trefoil_CS.
[Graphical view]
PfamiPF01055. Glyco_hydro_31. 2 hits.
PF00088. Trefoil. 1 hit.
[Graphical view]
SMARTiSM00018. PD. 2 hits.
[Graphical view]
SUPFAMiSSF51445. SSF51445. 4 hits.
SSF57492. SSF57492. 1 hit.
SSF74650. SSF74650. 2 hits.
PROSITEiPS00129. GLYCOSYL_HYDROL_F31_1. 2 hits.
PS00707. GLYCOSYL_HYDROL_F31_2. 1 hit.
PS00025. P_TREFOIL_1. 1 hit.
PS51448. P_TREFOIL_2. 2 hits.
[Graphical view]
ProtoNetiSearch...

Publicationsi

  1. "Cloning and sequencing of a full-length rat sucrase-isomaltase-encoding cDNA."
    Chandrasena G., Osterholm D.E., Sunitha I., Henning S.J.
    Gene 150:355-360(1994) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA].
    Strain: Sprague-Dawley.
    Tissue: Intestine.
  2. "Regulation of sucrase-isomaltase gene expression along the crypt-villus axis of rat small intestine."
    Traber P.G.
    Biochem. Biophys. Res. Commun. 173:765-773(1990) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 87-362.
    Strain: Fischer 344.
    Tissue: Intestine.
  3. "Molecular cloning and characterization of a rat intestinal sucrase-isomaltase cDNA. Regulation of sucrase-isomaltase gene expression by sucrose feeding."
    Broyart J.-P., Hugot J.-P., Perret C., Porteu A.
    Biochim. Biophys. Acta 1087:61-67(1990) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 733-1373.
    Strain: Sprague-Dawley.
    Tissue: Duodenum.
  4. "Biosynthesis of sucrase-isomaltase. Purification and NH2-terminal amino acid sequence of the rat sucrase-isomaltase precursor (pro-sucrase-isomaltase) from fetal intestinal transplants."
    Hauri H.-P., Wacker H., Rickli E.E., Bigler-Meier B., Quaroni A., Semenza G.
    J. Biol. Chem. 257:4522-4528(1982) [PubMed] [Europe PMC] [Abstract]
    Cited for: PROTEIN SEQUENCE OF N-TERMINUS OF ISOMALTASE AND SUCRASE.

Entry informationi

Entry nameiSUIS_RAT
AccessioniPrimary (citable) accession number: P23739
Entry historyi
Integrated into UniProtKB/Swiss-Prot: November 1, 1991
Last sequence update: January 23, 2007
Last modified: July 22, 2015
This is version 129 of the entry and version 5 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Miscellaneous

There is a high degree of homology between the isomaltase and sucrase portions (41% of amino acid identity) indicating that this protein is evolved by partial gene duplication.

Keywords - Technical termi

Complete proteome, Direct protein sequencing, Multifunctional enzyme, Reference proteome

Documents

  1. Glycosyl hydrolases
    Classification of glycosyl hydrolase families and list of entries
  2. SIMILARITY comments
    Index of protein domains and families

External Data

Dasty 3

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into Uniref entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.