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O62653 (SUIS_SUNMU) Reviewed, UniProtKB/Swiss-Prot

Last modified February 19, 2014. Version 89. 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
OrganismSuncus murinus (Asian house shrew) (Musk shrew)
Taxonomic identifier9378 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaLaurasiatheriaInsectivoraSoricidaeCrocidurinaeSuncus

Protein attributes

Sequence length1813 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at transcript 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 By similarity.

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 By similarity.

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 By similarity.

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.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Initiator methionine11Removed By similarity
Chain2 – 18131812Sucrase-isomaltase, intestinal
PRO_0000018562
Chain2 – 991990Isomaltase By similarity
PRO_0000018563
Chain992 – 1813822Sucrase By similarity
PRO_0000018564

Regions

Topological domain2 – 1211Cytoplasmic Potential
Transmembrane13 – 3220Helical; Signal-anchor for type II membrane protein; Potential
Topological domain33 – 18131781Lumenal Potential
Domain46 – 9550P-type 1
Domain917 – 96246P-type 2
Region95 – 991897Isomaltase
Region992 – 1813822Sucrase
Compositional bias42 – 454Ser/Thr-rich

Sites

Active site4911Nucleophile; for isomaltase activity By similarity
Active site5901For isomaltase activity By similarity
Active site13801Nucleophile; for sucrase activity By similarity
Active site13831For sucrase activity By similarity
Active site14861Proton donor; for sucrase activity By similarity
Binding site2501Substrate By similarity
Binding site3741Substrate By similarity
Binding site5741Substrate By similarity
Binding site6481Substrate By similarity

Amino acid modifications

Modified residue71Phosphoserine; by PKA By similarity
Modified residue3771Sulfotyrosine Potential
Modified residue12941Sulfotyrosine Potential
Modified residue13681Sulfotyrosine Potential
Modified residue13711Sulfotyrosine Potential
Glycosylation1271N-linked (GlcNAc...) Potential
Glycosylation3881N-linked (GlcNAc...) Potential
Glycosylation6691N-linked (GlcNAc...) Potential
Glycosylation7911N-linked (GlcNAc...) Potential
Glycosylation8961N-linked (GlcNAc...) Potential
Glycosylation9111N-linked (GlcNAc...) Potential
Glycosylation12211N-linked (GlcNAc...) Potential
Glycosylation12891N-linked (GlcNAc...) Potential
Glycosylation13261N-linked (GlcNAc...) Potential
Glycosylation13401N-linked (GlcNAc...) Potential
Glycosylation14321N-linked (GlcNAc...) Potential
Glycosylation15211N-linked (GlcNAc...) Potential
Glycosylation15451N-linked (GlcNAc...) Potential
Glycosylation15581N-linked (GlcNAc...) Potential
Glycosylation17031N-linked (GlcNAc...) Potential
Glycosylation17721N-linked (GlcNAc...) Potential
Disulfide bond48 ↔ 79 By similarity
Disulfide bond62 ↔ 78 By similarity
Disulfide bond73 ↔ 91 By similarity
Disulfide bond506 ↔ 531 By similarity
Disulfide bond621 ↔ 632 By similarity

Sequences

Sequence LengthMass (Da)Tools
O62653 [UniParc].

Last modified January 23, 2007. Version 3.
Checksum: 93DAE1B3952C7AD6

FASTA1,813208,305
        10         20         30         40         50         60 
MARKKSSGLK ITLIVLLAIV TIIAIALVAI LPTKTPAVEL VSTIPGKCPS AENDRLDEKI 

        70         80         90        100        110        120 
NCIPDQFPTQ ALCAMQGCCW NPRNESPTPW CSFANNHGYE FEKISNPNIN FEPNLKKNSP 

       130        140        150        160        170        180 
PTLFGDNITN LLLTTQSQTA NRFRFKITDP NNQRYEVPHQ FVNKDFSGPP ASNPLYDVKI 

       190        200        210        220        230        240 
TENPFSIKVI RKSNNKILFD TSIGPLVYSN QYLQISTKLP SKYIYGLGEH VHKRFRHDLY 

       250        260        270        280        290        300 
WKTWPIFTRD QLPGDNNNNL YGHQTFFMSI EDTSGKSFGV FLMNSNAMEV FIQPTPIVTY 

       310        320        330        340        350        360 
RVIGGILDFY IFLGDTPGQV VQQYQELTGR PAMPSYWSLG FQLSRWNYGS LDAVKEVVKR 

       370        380        390        400        410        420 
NRDARIPFDA QVTDIDYMED KKDFTYNNKT FYGLPEFVKD LHDHGQKYII ILDPAISITS 

       430        440        450        460        470        480 
LANGNHYKTY ERGNEQKVWV YQSDGTTPLI GEVWPGLTVY PDFTNPKCLD WWTNECSIFH 

       490        500        510        520        530        540 
EEIKYDGLWI DMNEVSSFVH GSTKGCSDNK LNYPPFIPDI LDKLMYAKTI CMDAIQHWGK 

       550        560        570        580        590        600 
QYDVHSLYGY SMAIATEKAI EKVFPNKRSF ILTRSTFAGT GKHATHWLGD NTPSWEHMEW 

       610        620        630        640        650        660 
SITPMLEFGL FGMPFIGADI CGFVVDTTEE LCRRWMQIGA FYPYFRDHNA GGYMPQDPAY 

       670        680        690        700        710        720 
FGQDSLLVNT SRHYLDIWYT LLPYLYNLLY KAYVYGETVA RPFLYEFYED TNSWIEDLQF 

       730        740        750        760        770        780 
LWGSALLITP VLRQGADRMS AYIPDATWYD YETGGKRTWR KQRVEMYLPG DKIGLHVRGG 

       790        800        810        820        830        840 
YIIPTQQPAV NTTASRKNPL GLIIALDNNA AKGDFFWDDG ESKDSIEKGK YILYTFSVLN 

       850        860        870        880        890        900 
NELDIICTHS SYQEGTTLAF ETIKILGLAN TVTQVQVAEN NQQTIIHNSF TYHASNQSLI 

       910        920        930        940        950        960 
IDNLKLNLGK NFTVQWNQVS LDSEKIDCFP DNNPENKQNC EERGCLWEPN SAAEGPRCYF 

       970        980        990       1000       1010       1020 
PKQYNPYLVK STQYSSMGIT VDLELNTATA RIKMPSNPIS VLRLEVKYHK NDMLQFKIYD 

      1030       1040       1050       1060       1070       1080 
PQNKRYEVPI PMDIPTTPTS TYENRLYDVN IKGNPFGIQI RRRSTGRIFW DSCLPWGLLL 

      1090       1100       1110       1120       1130       1140 
MNQFIQISTR LPSEYVYGFG GVGHRQFKQD LNWHKWGMFN RDQPSGYKIS SYGFQPYIYM 

      1150       1160       1170       1180       1190       1200 
ALGDGGNAHG VFLLNSNAMD VTFQPNPALT YRTIGGILDF YMFLGPNPEV ATKQYHEVIG 

      1210       1220       1230       1240       1250       1260 
RPVKPPYWAL GFHLCRYGYE NTSEIRQLYE DMVSAQIPYD VQYTDIDYME RQLDFTIGKG 

      1270       1280       1290       1300       1310       1320 
FQDLPEFVDK IRDEGMKYII ILDPAISGNE TQDYLAFQRG IEKDVFVKWP NTQDICWAKV 

      1330       1340       1350       1360       1370       1380 
WPDLPNITID DSLTEDEAVN ASRAHVAFPD FLKTSTAEWW ATEIEDFYNT YMKFDGLWID 

      1390       1400       1410       1420       1430       1440 
MNEPSSFVHG SVDNKCRNEI LNYPPYMPAL TKRNEGLHFR TMCMETQQTL SNGSSVLHYD 

      1450       1460       1470       1480       1490       1500 
VHNLYGWSQA KPTYDALQKT TGKRGIVISR STYPSAGRWA GHWLGDNYAN WDKIGKSIIG 

      1510       1520       1530       1540       1550       1560 
MMEFSLFGIS FTGADICGFF NNSDYELCAR WMQVGAFYPY SRNHNITDTR RQDPVSWNET 

      1570       1580       1590       1600       1610       1620 
FASMSTDILN IRYNLLPYFY TQMHDIHANG GTVIRPLLHE FFSETGTWDI YKQFLWGPAF 

      1630       1640       1650       1660       1670       1680 
MVTPVVEPYS ESVTGYVPDG RWLDYHTGQD IGLRKRLHTL DAPLYKINLH VCGGHILPCQ 

      1690       1700       1710       1720       1730       1740 
EPAQNTYFSR QNYMKLIVAA DDNQTAQGYL FWDDGESIDT YEKGQYLLVQ FNLNKATLTS 

      1750       1760       1770       1780       1790       1800 
TILKNGYINT REMRLGFINV WGKGNTVVQE VNITYKGNKE SVKFSQEANK QILNIDLTAN 

      1810 
NIVLDEPIEI SWT 

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References

[1]"Molecular cloning of sucrase-isomaltase cDNA in the house musk shrew Suncus murinus and identification of a mutation responsible for isolated sucrase deficiency."
Ito T., Hayashi Y., Ohmori S., Oda S., Seo H.
J. Biol. Chem. 273:16464-16469(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA].

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
AB011401 mRNA. Translation: BAA25370.1.

3D structure databases

ProteinModelPortalO62653.
SMRO62653. Positions 56-917.
ModBaseSearch...
MobiDBSearch...

Protein family/group databases

CAZyGH31. Glycoside Hydrolase Family 31.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Phylogenomic databases

HOVERGENHBG080721.

Enzyme and pathway databases

SABIO-RKO62653.

Family and domain databases

Gene3D4.10.110.10. 2 hits.
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. 2 hits.
[Graphical view]
SMARTSM00018. PD. 2 hits.
[Graphical view]
SUPFAMSSF51445. SSF51445. 4 hits.
SSF74650. SSF74650. 2 hits.
PROSITEPS00129. GLYCOSYL_HYDROL_F31_1. 2 hits.
PS00707. GLYCOSYL_HYDROL_F31_2. 2 hits.
PS00025. P_TREFOIL_1. 1 hit.
PS51448. P_TREFOIL_2. 2 hits.
[Graphical view]
ProtoNetSearch...

Entry information

Entry nameSUIS_SUNMU
AccessionPrimary (citable) accession number: O62653
Entry history
Integrated into UniProtKB/Swiss-Prot: May 30, 2000
Last sequence update: January 23, 2007
Last modified: February 19, 2014
This is version 89 of the entry and version 3 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