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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)DescriptionActionsGraphical viewLength
Binding sitei274SubstrateBy similarity1
Binding sitei398SubstrateBy similarity1
Active sitei514Nucleophile; for isomaltase activityPROSITE-ProRule annotation1
Binding sitei599SubstrateBy similarity1
Active sitei615For isomaltase activityBy similarity1
Binding sitei673SubstrateBy similarity1
Active sitei1399Nucleophile; for sucrase activityPROSITE-ProRule annotation1
Active sitei1402For sucrase activityBy similarity1
Active sitei1512Proton donor; for sucrase activityBy similarity1

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
Proteomesi
  • UP000002494 Componenti: Unplaced

Organism-specific databases

RGDi3675. Si.

Subcellular locationi

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini2 – 12CytoplasmicSequence analysisAdd BLAST11
Transmembranei13 – 32Helical; Signal-anchor for type II membrane proteinSequence analysisAdd BLAST20
Topological domaini33 – 1841LumenalSequence analysisAdd BLAST1809

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

Pathology & Biotechi

Chemistry databases

ChEMBLiCHEMBL3114.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Initiator methionineiRemovedBy similarity
ChainiPRO_00000185592 – 1841Sucrase-isomaltase, intestinalAdd BLAST1840
ChainiPRO_00000185602 – 1013IsomaltaseAdd BLAST1012
ChainiPRO_00000185611014 – 1841SucraseAdd BLAST828

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei7Phosphoserine; by PKABy similarity1
Disulfide bondi73 ↔ 104PROSITE-ProRule annotation
Disulfide bondi87 ↔ 103PROSITE-ProRule annotation
Disulfide bondi98 ↔ 116PROSITE-ProRule annotation
Glycosylationi109N-linked (GlcNAc...)Sequence analysis1
Modified residuei401SulfotyrosineSequence analysis1
Modified residuei410SulfotyrosineSequence analysis1
Glycosylationi464N-linked (GlcNAc...)Sequence analysis1
Disulfide bondi646 ↔ 657PROSITE-ProRule annotation
Glycosylationi758N-linked (GlcNAc...)Sequence analysis1
Glycosylationi765N-linked (GlcNAc...)Sequence analysis1
Glycosylationi867N-linked (GlcNAc...)Sequence analysis1
Glycosylationi910N-linked (GlcNAc...)Sequence analysis1
Glycosylationi1240N-linked (GlcNAc...)Sequence analysis1
Glycosylationi1308N-linked (GlcNAc...)Sequence analysis1
Glycosylationi1345N-linked (GlcNAc...)Sequence analysis1
Glycosylationi1359N-linked (GlcNAc...)Sequence analysis1
Glycosylationi1373N-linked (GlcNAc...)Sequence analysis1
Modified residuei1387SulfotyrosineSequence analysis1
Glycosylationi1485N-linked (GlcNAc...)Sequence analysis1
Glycosylationi1513N-linked (GlcNAc...)Sequence analysis1
Glycosylationi1575N-linked (GlcNAc...)Sequence analysis1
Glycosylationi1762N-linked (GlcNAc...)Sequence analysis1
Glycosylationi1829N-linked (GlcNAc...)Sequence analysis1

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

iPTMnetiP23739.
PhosphoSitePlusiP23739.

Interactioni

Subunit structurei

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

Chemistry databases

BindingDBiP23739.

Structurei

3D structure databases

ProteinModelPortaliP23739.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini71 – 120P-type 1PROSITE-ProRule annotationAdd BLAST50
Domaini936 – 984P-type 2PROSITE-ProRule annotationAdd BLAST49

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni120 – 1013IsomaltaseAdd BLAST894
Regioni1014 – 1841SucraseAdd BLAST828

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Compositional biasi43 – 70Ser/Thr-richAdd BLAST28

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

HOGENOMiHOG000067936.
HOVERGENiHBG080721.
InParanoidiP23739.
KOiK01203.
PhylomeDBiP23739.

Family and domain databases

CDDicd00111. Trefoil. 2 hits.
Gene3Di4.10.110.10. 2 hits.
InterProiIPR031727. Gal_mutarotase_N.
IPR011013. Gal_mutarotase_SF_dom.
IPR000322. Glyco_hydro_31.
IPR030458. Glyco_hydro_31_AS.
IPR030459. Glyco_hydro_31_CS.
IPR017853. Glycoside_hydrolase_SF.
IPR017957. P_trefoil_CS.
IPR000519. P_trefoil_dom.
[Graphical view]
PfamiPF01055. Glyco_hydro_31. 2 hits.
PF16863. NtCtMGAM_N. 2 hits.
PF00088. Trefoil. 2 hits.
[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)DescriptionActionsGraphical viewLength
Sequence conflicti87C → W in AAA65097 (PubMed:7821806).Curated1
Sequence conflicti92H → S in AAA42144 (PubMed:2268340).Curated1
Sequence conflicti95K → Q in AAA42144 (PubMed:2268340).Curated1
Sequence conflicti736E → V in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti842E → Q in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti916A → T in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti924A → R in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti930 – 931AG → GT in CAA33552 (PubMed:2400788).Curated2
Sequence conflicti938 – 939CR → SQ in CAA33552 (PubMed:2400788).Curated2
Sequence conflicti959 – 962GTCT → ETDK in CAA33552 (PubMed:2400788).Curated4
Sequence conflicti980Y → C in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti986N → H in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti997 – 998LP → SL in CAA33552 (PubMed:2400788).Curated2
Sequence conflicti1010P → A in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti1023T → P in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti1027G → E in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti1032P → K in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti1094R → S in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti1099G → A in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti1302A → D in CAA33552 (PubMed:2400788).Curated1
Sequence conflicti1337 – 1340PKVW → AKWG in CAA33552 (PubMed:2400788).Curated4

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.
ModBaseiSearch...
MobiDBiSearch...

Chemistry databases

BindingDBiP23739.
ChEMBLiCHEMBL3114.

Protein family/group databases

CAZyiGH31. Glycoside Hydrolase Family 31.

PTM databases

iPTMnetiP23739.
PhosphoSitePlusiP23739.

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

HOGENOMiHOG000067936.
HOVERGENiHBG080721.
InParanoidiP23739.
KOiK01203.
PhylomeDBiP23739.

Enzyme and pathway databases

BRENDAi3.2.1.10. 5301.
SABIO-RKP23739.

Miscellaneous databases

PROiP23739.

Family and domain databases

CDDicd00111. Trefoil. 2 hits.
Gene3Di4.10.110.10. 2 hits.
InterProiIPR031727. Gal_mutarotase_N.
IPR011013. Gal_mutarotase_SF_dom.
IPR000322. Glyco_hydro_31.
IPR030458. Glyco_hydro_31_AS.
IPR030459. Glyco_hydro_31_CS.
IPR017853. Glycoside_hydrolase_SF.
IPR017957. P_trefoil_CS.
IPR000519. P_trefoil_dom.
[Graphical view]
PfamiPF01055. Glyco_hydro_31. 2 hits.
PF16863. NtCtMGAM_N. 2 hits.
PF00088. Trefoil. 2 hits.
[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...

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: November 30, 2016
This is version 139 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

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 one 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.