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P23739 (SUIS_RAT) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 121. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Sucrase-isomaltase, intestinal

Cleaved into the following 2 chains:

  1. Sucrase
    EC=3.2.1.48
  2. Isomaltase
    EC=3.2.1.10
Gene names
Name:Si
OrganismRattus norvegicus (Rat) [Reference proteome]
Taxonomic identifier10116 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeRattus

Protein attributes

Sequence length1841 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

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 activity

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.

Subunit structure

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

Subcellular location

Apical cell membrane; Single-pass type II membrane protein. Note: Brush border.

Post-translational modification

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

Sulfated By similarity.

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.

Sequence similarities

Belongs to the glycosyl hydrolase 31 family.

Contains 2 P-type (trefoil) domains.

Ontologies

Keywords
   Cellular componentCell membrane
Membrane
   DomainRepeat
Signal-anchor
Transmembrane
Transmembrane helix
   Molecular functionGlycosidase
Hydrolase
   PTMDisulfide bond
Glycoprotein
Phosphoprotein
Sulfation
   Technical termComplete proteome
Direct protein sequencing
Multifunctional enzyme
Reference proteome
Gene Ontology (GO)
   Biological_processaging

Inferred from expression pattern PubMed 9202095. Source: RGD

carbohydrate metabolic process

Inferred from electronic annotation. Source: InterPro

response to fructose

Inferred from expression pattern PubMed 15539244. Source: RGD

response to glucocorticoid

Inferred from expression pattern PubMed 9618286. Source: RGD

response to insulin

Inferred from expression pattern PubMed 9585003. Source: RGD

response to nutrient

Inferred from expression pattern PubMed 7873573. Source: RGD

response to starvation

Inferred from expression pattern PubMed 10864000. Source: RGD

response to sucrose

Inferred from expression pattern PubMed 8890076. Source: RGD

response to vitamin A

Inferred from expression pattern PubMed 15309444. Source: RGD

   Cellular_componentapical plasma membrane

Inferred from electronic annotation. Source: UniProtKB-SubCell

brush border

Inferred from direct assay PubMed 15138292. Source: RGD

integral component of membrane

Inferred from electronic annotation. Source: UniProtKB-KW

membrane raft

Inferred from direct assay PubMed 15138292. Source: RGD

   Molecular_functionbeta-fructofuranosidase activity

Inferred from direct assay Ref.4. Source: RGD

carbohydrate binding

Inferred from electronic annotation. Source: InterPro

oligo-1,6-glucosidase activity

Inferred from direct assay Ref.4. Source: RGD

sucrose alpha-glucosidase activity

Inferred from electronic annotation. Source: UniProtKB-EC

Complete GO annotation...

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Initiator methionine11Removed By similarity
Chain2 – 18411840Sucrase-isomaltase, intestinal
PRO_0000018559
Chain2 – 10131012Isomaltase
PRO_0000018560
Chain1014 – 1841828Sucrase
PRO_0000018561

Regions

Topological domain2 – 1211Cytoplasmic Potential
Transmembrane13 – 3220Helical; Signal-anchor for type II membrane protein; Potential
Topological domain33 – 18411809Lumenal Potential
Domain71 – 12050P-type 1
Domain936 – 98449P-type 2
Region120 – 1013894Isomaltase
Region1014 – 1841828Sucrase
Compositional bias43 – 7028Ser/Thr-rich

Sites

Active site5141Nucleophile; for isomaltase activity By similarity
Active site6151For isomaltase activity By similarity
Active site13991Nucleophile; for sucrase activity By similarity
Active site14021For sucrase activity By similarity
Active site15121Proton donor; for sucrase activity By similarity
Binding site2741Substrate By similarity
Binding site3981Substrate By similarity
Binding site5991Substrate By similarity
Binding site6731Substrate By similarity

Amino acid modifications

Modified residue71Phosphoserine; by PKA By similarity
Modified residue4011Sulfotyrosine Potential
Modified residue4101Sulfotyrosine Potential
Modified residue13871Sulfotyrosine Potential
Glycosylation1091N-linked (GlcNAc...) Potential
Glycosylation4641N-linked (GlcNAc...) Potential
Glycosylation7581N-linked (GlcNAc...) Potential
Glycosylation7651N-linked (GlcNAc...) Potential
Glycosylation8671N-linked (GlcNAc...) Potential
Glycosylation9101N-linked (GlcNAc...) Potential
Glycosylation12401N-linked (GlcNAc...) Potential
Glycosylation13081N-linked (GlcNAc...) Potential
Glycosylation13451N-linked (GlcNAc...) Potential
Glycosylation13591N-linked (GlcNAc...) Potential
Glycosylation13731N-linked (GlcNAc...) Potential
Glycosylation14851N-linked (GlcNAc...) Potential
Glycosylation15131N-linked (GlcNAc...) Potential
Glycosylation15751N-linked (GlcNAc...) Potential
Glycosylation17621N-linked (GlcNAc...) Potential
Glycosylation18291N-linked (GlcNAc...) Potential
Disulfide bond73 ↔ 104 By similarity
Disulfide bond87 ↔ 103 By similarity
Disulfide bond98 ↔ 116 By similarity
Disulfide bond646 ↔ 657 By similarity

Experimental info

Sequence conflict871C → W in AAA65097. Ref.1
Sequence conflict921H → S in AAA42144. Ref.2
Sequence conflict951K → Q in AAA42144. Ref.2
Sequence conflict7361E → V in CAA33552. Ref.3
Sequence conflict8421E → Q in CAA33552. Ref.3
Sequence conflict9161A → T in CAA33552. Ref.3
Sequence conflict9241A → R in CAA33552. Ref.3
Sequence conflict930 – 9312AG → GT in CAA33552. Ref.3
Sequence conflict938 – 9392CR → SQ in CAA33552. Ref.3
Sequence conflict959 – 9624GTCT → ETDK in CAA33552. Ref.3
Sequence conflict9801Y → C in CAA33552. Ref.3
Sequence conflict9861N → H in CAA33552. Ref.3
Sequence conflict997 – 9982LP → SL in CAA33552. Ref.3
Sequence conflict10101P → A in CAA33552. Ref.3
Sequence conflict10231T → P in CAA33552. Ref.3
Sequence conflict10271G → E in CAA33552. Ref.3
Sequence conflict10321P → K in CAA33552. Ref.3
Sequence conflict10941R → S in CAA33552. Ref.3
Sequence conflict10991G → A in CAA33552. Ref.3
Sequence conflict13021A → D in CAA33552. Ref.3
Sequence conflict1337 – 13404PKVW → AKWG in CAA33552. Ref.3

Sequences

Sequence LengthMass (Da)Tools
P23739 [UniParc].

Last modified January 23, 2007. Version 5.
Checksum: E186B8632475EE09

FASTA1,841210,350
        10         20         30         40         50         60 
MAKKKFSALE ISLIVLFIIV TAIAIALVTV LATKVPAVEE IKSPTPTSNS TPTSTPTSTS 

        70         80         90        100        110        120 
TPTSTSTPSP GKCPPEQGEP INERINCIPE QHPTKAICEE RGCCWRPWNN TVIPWCFFAD 

       130        140        150        160        170        180 
NHGYNAESIT NENAGLKATL NRIPSPTLFG EDIKSVILTT QTQTGNRFRF KITDPNNKRY 

       190        200        210        220        230        240 
EVPHQFVKEE TGIPAADTLY DVQVSENPFS IKVIRKSNNK VLCDTSVGPL LYSNQYLQIS 

       250        260        270        280        290        300 
TRLPSEYIYG FGGHIHKRFR HDLYWKTWPI FTRDEIPGDN NHNLYGHQTF FMGIGDTSGK 

       310        320        330        340        350        360 
SYGVFLMNSN AMEVFIQPTP IITYRVTGGI LDFYIFLGDT PEQVVQQYQE VHWRPAMPAY 

       370        380        390        400        410        420 
WNLGFQLSRW NYGSLDTVSE VVRRNREAGI PYDAQVTDID YMEDHKEFTY DRVKFNGLPE 

       430        440        450        460        470        480 
FAQDLHNHGK YIIILDPAIS INKRANGAEY QTYVRGNEKN VWVNESDGTT PLIGEVWPGL 

       490        500        510        520        530        540 
TVYPDFTNPQ TIEWWANECN LFHQQVEYDG LWIDMNEVSS FIQGSLNLKG VLLIVLNYPP 

       550        560        570        580        590        600 
FTPGILDKVM YSKTLCMDAV QHWGKQYDVH SLYGYSMAIA TEQAVERVFP NKRSFILTRS 

       610        620        630        640        650        660 
TFGGSGRHAN HWLGDNTASW EQMEWSITGM LEFGIFGMPL VGATSCGFLA DTTEELCRRW 

       670        680        690        700        710        720 
MQLGAFYPFS RNHNAEGYME QDPAYFGQDS SRHYLTIRYT LLPFLYTLFY RAHMFGETVA 

       730        740        750        760        770        780 
RPFLYEFYDD TNSWIEDTQF LWGPALLITP VLRPGVENVS AYIPNATWYD YETGIKRPWR 

       790        800        810        820        830        840 
KERINMYLPG DKIGLHLRGG YIIPTQEPDV TTTASRKNPL GLIVALDDNQ AAKGELFWDD 

       850        860        870        880        890        900 
GESKDSIEKK MYILYTFSVS NNELVLNCTH SSYAEGTSLA FKTIKVLGLR EDVRSITVGE 

       910        920        930        940        950        960 
NDQQMATHTN FTFDSANKIL SITALNFNLA GSFIVRWCRT FSDNEKFTCY PDVGTATEGT 

       970        980        990       1000       1010       1020 
CTQRGCLWQP VSGLSNVPPY YFPPENNPYT LTSIQPLPTG ITAELQLNPP NARIKLPSNP 

      1030       1040       1050       1060       1070       1080 
ISTLRVGVKY HPNDMLQFKI YDAQHKRYEV PVPLNIPDTP TSSNERLYDV EIKENPFGIQ 

      1090       1100       1110       1120       1130       1140 
VRRRSSGKLI WDSRLPGFGF NDQFIQISTR LPSNYLYGFG EVEHTAFKRD LNWHTWGMFT 

      1150       1160       1170       1180       1190       1200 
RDQPPGYKLN SYGFHPYYMA LENEGNAHGV LLLNSNGMDV TFQPTPALTY RTIGGILDFY 

      1210       1220       1230       1240       1250       1260 
MFLGPTPEIA TRQYHEVIGF PVMPPYWALG FQLCRYGYRN TSEIEQLYND MVAANIPYDV 

      1270       1280       1290       1300       1310       1320 
QYTDINYMER QLDFTIGERF KTLPEFVDRI RKDGMKYIVI LAPAISGNET QPYPAFERGI 

      1330       1340       1350       1360       1370       1380 
QKDVFVKWPN TNDICWPKVW PDLPNVTIDE TITEDEAVNA SRAHVAFPDF FRNSTLEWWA 

      1390       1400       1410       1420       1430       1440 
REIYDFYNEK MKFDGLWIDM NEPSSFGIQM GGKVLNECRR MMTLNYPPVF SPELRVKEGE 

      1450       1460       1470       1480       1490       1500 
GASISEAMCM ETEHILIDGS SVLQYDVHNL YGWSQVKPTL DALQNTTGLR GIVISRSTYP 

      1510       1520       1530       1540       1550       1560 
TTGRWGGHWL GDNYTTWDNL EKSLIGMLEL NLFGIPYIGA DICGVFHDSG YPSLYFVGIQ 

      1570       1580       1590       1600       1610       1620 
VGAFYPYPRE SPTINFTRSQ DPVSWMKLLL QMSKKVLEIR YTLLPYFYTQ MHEAHAHGGT 

      1630       1640       1650       1660       1670       1680 
VIRPLMHEFF DDKETWEIYK QFLWGPAFMV TPVVEPFRTS VTGYVPKARW FDYHTGADIK 

      1690       1700       1710       1720       1730       1740 
LKGILHTFSA PFDTINLHVR GGYILPCQEP ARNTHLSRQN YMKLIVAADD NQMAQGTLFG 

      1750       1760       1770       1780       1790       1800 
DDGESIDTYE RGQYTSIQFN LNQTTLTSTV LANGYKNKQE MRLGSIHIWG KGTLRISNAN 

      1810       1820       1830       1840 
LVYGGRKHQP PFTQEEAKET LIFDLKNMNV TLDEPIQITW S 

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References

[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.
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
L25926 mRNA. Translation: AAA65097.1.
M62889 mRNA. Translation: AAA42144.1.
X15546 mRNA. Translation: CAA33552.1.
PIRS11386.
T10799.
RefSeqNP_037193.1. NM_013061.1.
UniGeneRn.10057.

3D structure databases

ProteinModelPortalP23739.
SMRP23739. Positions 83-937.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

STRING10116.ENSRNOP00000045106.

Chemistry

BindingDBP23739.
ChEMBLCHEMBL3114.

Protein family/group databases

CAZyGH31. Glycoside Hydrolase Family 31.

PTM databases

PhosphoSiteP23739.

Proteomic databases

PRIDEP23739.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

GeneID497756.
KEGGrno:497756.
UCSCRGD:3675. rat.

Organism-specific databases

CTD6476.
RGD3675. Si.

Phylogenomic databases

eggNOGCOG1501.
HOGENOMHOG000067936.
HOVERGENHBG080721.
KOK01203.
PhylomeDBP23739.

Enzyme and pathway databases

BRENDA3.2.1.10. 5301.
SABIO-RKP23739.

Gene expression databases

GenevestigatorP23739.

Family and domain databases

Gene3D4.10.110.10. 1 hit.
InterProIPR011013. Gal_mutarotase_SF_dom.
IPR000322. Glyco_hydro_31.
IPR017853. Glycoside_hydrolase_SF.
IPR000519. P_trefoil.
IPR017957. P_trefoil_CS.
[Graphical view]
PfamPF01055. Glyco_hydro_31. 2 hits.
PF00088. Trefoil. 1 hit.
[Graphical view]
SMARTSM00018. PD. 2 hits.
[Graphical view]
SUPFAMSSF51445. SSF51445. 4 hits.
SSF57492. SSF57492. 1 hit.
SSF74650. SSF74650. 2 hits.
PROSITEPS00129. 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]
ProtoNetSearch...

Other

NextBio697744.
PROP23739.

Entry information

Entry nameSUIS_RAT
AccessionPrimary (citable) accession number: P23739
Entry history
Integrated into UniProtKB/Swiss-Prot: November 1, 1991
Last sequence update: January 23, 2007
Last modified: April 16, 2014
This is version 121 of the entry and version 5 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

Glycosyl hydrolases

Classification of glycosyl hydrolase families and list of entries