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Reviewed, UniProtKB/Swiss-Prot O43451 (MGA_HUMAN)

Last modified June 16, 2009. Version 87. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (7) | Third-party data | Customize display text xml rdf/xml gff fasta
Names and origin · Protein attributes · General annotation (Comments) · Ontologies · Sequence annotation (Features) · Sequences · References · Cross-references · Entry information · Relevant documents

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Names and origin

Protein namesRecommended name:
    Maltase-glucoamylase, intestinal
Including the following 2 domains:
    1- Recommended name:
            Maltase
              EC=3.2.1.20
        Alternative name(s):
            Alpha-glucosidase
    2- Recommended name:
            Glucoamylase
              EC=3.2.1.3
        Alternative name(s):
            Glucan 1,4-alpha-glucosidase
Gene names
Name: MGAM
Synonyms: MGA, MGAML
OrganismHomo sapiens (Human)
Taxonomic identifier9606 [NCBI]
Taxonomic lineageEukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo

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Protein attributes

Sequence length1857 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level.

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General annotation (Comments)

Function

May serve as an alternate pathway for starch digestion when luminal alpha-amylase activity is reduced because of immaturity or malnutrition. May play a unique role in the digestion of malted dietary oligosaccharides used in food manufacturing.

Catalytic activity

Hydrolysis of terminal, non-reducing (1->4)-linked alpha-D-glucose residues with release of alpha-D-glucose.

Hydrolysis of terminal (1->4)-linked alpha-D-glucose residues successively from non-reducing ends of the chains with release of beta-D-glucose.

Subunit structure

Monomer.

Subcellular location

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

Tissue specificity

Expressed in small intestine, granulocyte, and kidney but not in salivary gland or pancreas.

Post-translational modification

N- and O-glycosylated. Ref.7

Does not undergo intracellular or extracellular proteolytic cleavage.

Sulfated By similarity.

Sequence similarities

Belongs to the glycosyl hydrolase 31 family.

Contains 2 P-type (trefoil) domains.

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Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Initiator methionine11Removed
Chain2 – 18571856Maltase-glucoamylase, intestinal
PRO_0000185363

Regions

Topological domain2 – 1312Cytoplasmic Potential
Transmembrane14 – 3421Signal-anchor for type II membrane protein Potential
Topological domain35 – 18571823Lumenal Potential
Domain88 – 13447P-type 1
Domain954 – 100047P-type 2
Region198 – 915718Maltase
Region1067 – 1813747Glucoamylase
Compositional bias38 – 8447Ser/Thr-rich

Sites

Active site5291Nucleophile By similarity
Active site5321 By similarity
Active site14201Nucleophile By similarity
Active site14231 By similarity
Active site15261Proton donor By similarity

Amino acid modifications

Modified residue4161Sulfotyrosine Potential
Modified residue4251Sulfotyrosine Potential
Modified residue12821Sulfotyrosine Potential
Glycosylation1351N-linked (GlcNAc...) Potential
Glycosylation2951N-linked (GlcNAc...)
Glycosylation4571N-linked (GlcNAc...) Potential
Glycosylation4581N-linked (GlcNAc...) Potential
Glycosylation4791N-linked (GlcNAc...)
Glycosylation7071N-linked (GlcNAc...) Potential
Glycosylation7491N-linked (GlcNAc...) Potential
Glycosylation8271N-linked (GlcNAc...)
Glycosylation8851N-linked (GlcNAc...) Potential
Glycosylation9121N-linked (GlcNAc...) Potential
Glycosylation9771N-linked (GlcNAc...) Potential
Glycosylation9891N-linked (GlcNAc...) Potential
Glycosylation12551N-linked (GlcNAc...) Potential
Glycosylation13231N-linked (GlcNAc...) Potential
Glycosylation13641N-linked (GlcNAc...) Potential
Glycosylation13881N-linked (GlcNAc...) Potential
Glycosylation16031N-linked (GlcNAc...) Potential
Glycosylation16721N-linked (GlcNAc...) Potential
Glycosylation18421N-linked (GlcNAc...) Potential
Glycosylation18471N-linked (GlcNAc...) Potential
Disulfide bond90 ↔ 118 By similarity
Disulfide bond101 ↔ 117 Ref.7
Disulfide bond112 ↔ 130 Ref.7
Disulfide bond659 ↔ 670 Ref.7
Disulfide bond966 ↔ 983 By similarity
Disulfide bond978 ↔ 996 By similarity

Natural variations

Natural variant4041Q → H: dbSNP rs2272330.
VAR_047350
Natural variant5421S → L: dbSNP rs10266732.
VAR_047351
Natural variant8581N → D: dbSNP rs2960746. Ref.1 Ref.4
VAR_047352
Natural variant16381L → I: dbSNP rs9655651.
VAR_047353

Experimental info

Sequence conflict8541L → P in AAI20873. Ref.4

Secondary structure

1 ........................................................................................................................................................ 1857
Helix Strand Turn

Details...

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Sequences

Sequence LengthMass (Da)Tools
O43451-1 [UniParc].

Last modified November 25, 2008. Version 5.
Checksum: 166EEC045C2031F7

FASTA1,857209,852
        10         20         30         40         50         60 
MARKKLKKFT TLEIVLSVLL LVLFIISIVL IVLLAKESLK STAPDPGTTG TPDPGTTGTP 

        70         80         90        100        110        120 
DPGTTGTTHA RTTGPPDPGT TGTTPVSAEC PVVNELERIN CIPDQPPTKA TCDQRGCCWN 

       130        140        150        160        170        180 
PQGAVSVPWC YYSKNHSYHV EGNLVNTNAG FTARLKNLPS SPVFGSNVDN VLLTAEYQTS 

       190        200        210        220        230        240 
NRFHFKLTDQ TNNRFEVPHE HVQSFSGNAA ASLTYQVEIS RQPFSIKVTR RSNNRVLFDS 

       250        260        270        280        290        300 
SIGPLLFADQ FLQLSTRLPS TNVYGLGEHV HQQYRHDMNW KTWPIFNRDT TPNGNGTNLY 

       310        320        330        340        350        360 
GAQTFFLCLE DASGLSFGVF LMNSNAMEVV LQPAPAITYR TIGGILDFYV FLGNTPEQVV 

       370        380        390        400        410        420 
QEYLELIGRP ALPSYWALGF HLSRYEYGTL DNMREVVERN RAAQLPYDVQ HADIDYMDER 

       430        440        450        460        470        480 
RDFTYDSVDF KGFPEFVNEL HNNGQKLVII VDPAISNNSS SSKPYGPYDR GSDMKIWVNS 

       490        500        510        520        530        540 
SDGVTPLIGE VWPGQTVFPD YTNPNCAVWW TKEFELFHNQ VEFDGIWIDM NEVSNFVDGS 

       550        560        570        580        590        600 
VSGCSTNNLN NPPFTPRILD GYLFCKTLCM DAVQHWGKQY DIHNLYGYSM AVATAEAAKT 

       610        620        630        640        650        660 
VFPNKRSFIL TRSTFAGSGK FAAHWLGDNT ATWDDLRWSI PGVLEFNLFG IPMVGPDICG 

       670        680        690        700        710        720 
FALDTPEELC RRWMQLGAFY PFSRNHNGQG YKDQDPASFG ADSLLLNSSR HYLNIRYTLL 

       730        740        750        760        770        780 
PYLYTLFFRA HSRGDTVARP LLHEFYEDNS TWDVHQQFLW GPGLLITPVL DEGAEKVMAY 

       790        800        810        820        830        840 
VPDAVWYDYE TGSQVRWRKQ KVEMELPGDK IGLHLRGGYI FPTQQPNTTT LASRKNPLGL 

       850        860        870        880        890        900 
IIALDENKEA KGELFWDNGE TKDTVANKVY LLCEFSVTQN RLEVNISQST YKDPNNLAFN 

       910        920        930        940        950        960 
EIKILGTEEP SNVTVKHNGV PSQTSPTVTY DSNLKVAIIT DIDLLLGEAY TVEWSIKIRD 

       970        980        990       1000       1010       1020 
EEKIDCYPDE NGASAENCTA RGCIWEASNS SGVPFCYFVN DLYSVSDVQY NSHGATADIS 

      1030       1040       1050       1060       1070       1080 
LKSSVYANAF PSTPVNPLRL DVTYHKNEML QFKIYDPNKN RYEVPVPLNI PSMPSSTPEG 

      1090       1100       1110       1120       1130       1140 
QLYDVLIKKN PFGIEIRRKS TGTIIWDSQL LGFTFSDMFI RISTRLPSKY LYGFGETEHR 

      1150       1160       1170       1180       1190       1200 
SYRRDLEWHT WGMFSRDQPP GYKKNSYGVH PYYMGLEEDG SAHGVLLLNS NAMDVTFQPL 

      1210       1220       1230       1240       1250       1260 
PALTYRTTGG VLDFYVFLGP TPELVTQQYT ELIGRPVMVP YWSLGFQLCR YGYQNDSEIA 

      1270       1280       1290       1300       1310       1320 
SLYDEMVAAQ IPYDVQYSDI DYMERQLDFT LSPKFAGFPA LINRMKADGM RVILILDPAI 

      1330       1340       1350       1360       1370       1380 
SGNETQPYPA FTRGVEDDVF IKYPNDGDIV WGKVWPDFPD VVVNGSLDWD SQVELYRAYV 

      1390       1400       1410       1420       1430       1440 
AFPDFFRNST AKWWKREIEE LYNNPQNPER SLKFDGMWID MNEPSSFVNG AVSPGCRDAS 

      1450       1460       1470       1480       1490       1500 
LNHPPYMPHL ESRDRGLSSK TLCMESQQIL PDGSLVQHYN VHNLYGWSQT RPTYEAVQEV 

      1510       1520       1530       1540       1550       1560 
TGQRGVVITR STFPSSGRWA GHWLGDNTAA WDQLKKSIIG MMEFSLFGIS YTGADICGFF 

      1570       1580       1590       1600       1610       1620 
QDAEYEMCVR WMQLGAFYPF SRNHNTIGTR RQDPVSWDVA FVNISRTVLQ TRYTLLPYLY 

      1630       1640       1650       1660       1670       1680 
TLMHKAHTEG VTVVRPLLHE FVSDQVTWDI DSQFLLGPAF LVSPVLERNA RNVTAYFPRA 

      1690       1700       1710       1720       1730       1740 
RWYDYYTGVD INARGEWKTL PAPLDHINLH VRGGYILPWQ EPALNTHLSR QKFMGFKIAL 

      1750       1760       1770       1780       1790       1800 
DDEGTAGGWL FWDDGQSIDT YGKGLYYLAS FSASQNTMQS HIIFNNYITG TNPLKLGYIE 

      1810       1820       1830       1840       1850 
IWGVGSVPVT SVSISVSGMV ITPSFNNDPT TQVLSIDVTD RNISLHNFTS LTWISTL

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References

« Hide 'large scale' references
[1]"Human small intestinal maltase-glucoamylase cDNA cloning. Homology to sucrase-isomaltase."
Nichols B.L., Eldering J.A., Avery S.E., Hahn D., Quaroni A., Sterchi E.E.
J. Biol. Chem. 273:3076-3081(1998) [PubMed: 9446624] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA], PARTIAL PROTEIN SEQUENCE, VARIANT ASP-858.
Tissue: Small intestine.
[2]Nichols B.L., Eldering J.A., Avery S.E., Hahn D., Quaroni A., Sterchi E.E.
Submitted (DEC-2001) to the EMBL/GenBank/DDBJ databases
Cited for: SEQUENCE REVISION TO 777; 1050; 1101; 1542; 1613 AND 1812.
[3]"The DNA sequence of human chromosome 7."
Hillier L.W., Fulton R.S., Fulton L.A., Graves T.A., Pepin K.H., Wagner-McPherson C., Layman D., Maas J., Jaeger S., Walker R., Wylie K., Sekhon M., Becker M.C., O'Laughlin M.D., Schaller M.E., Fewell G.A., Delehaunty K.D., Miner T.L. expand/collapse author list , Nash W.E., Cordes M., Du H., Sun H., Edwards J., Bradshaw-Cordum H., Ali J., Andrews S., Isak A., Vanbrunt A., Nguyen C., Du F., Lamar B., Courtney L., Kalicki J., Ozersky P., Bielicki L., Scott K., Holmes A., Harkins R., Harris A., Strong C.M., Hou S., Tomlinson C., Dauphin-Kohlberg S., Kozlowicz-Reilly A., Leonard S., Rohlfing T., Rock S.M., Tin-Wollam A.-M., Abbott A., Minx P., Maupin R., Strowmatt C., Latreille P., Miller N., Johnson D., Murray J., Woessner J.P., Wendl M.C., Yang S.-P., Schultz B.R., Wallis J.W., Spieth J., Bieri T.A., Nelson J.O., Berkowicz N., Wohldmann P.E., Cook L.L., Hickenbotham M.T., Eldred J., Williams D., Bedell J.A., Mardis E.R., Clifton S.W., Chissoe S.L., Marra M.A., Raymond C., Haugen E., Gillett W., Zhou Y., James R., Phelps K., Iadanoto S., Bubb K., Simms E., Levy R., Clendenning J., Kaul R., Kent W.J., Furey T.S., Baertsch R.A., Brent M.R., Keibler E., Flicek P., Bork P., Suyama M., Bailey J.A., Portnoy M.E., Torrents D., Chinwalla A.T., Gish W.R., Eddy S.R., McPherson J.D., Olson M.V., Eichler E.E., Green E.D., Waterston R.H., Wilson R.K.
Nature 424:157-164(2003) [PubMed: 12853948] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[4]"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
The MGC Project Team
Genome Res. 14:2121-2127(2004) [PubMed: 15489334] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA], VARIANT ASP-858.
[5]"Structure, biosynthesis, and glycosylation of human small intestinal maltase-glucoamylase."
Naim H.Y., Sterchi E.E., Lentze M.J.
J. Biol. Chem. 263:19709-19717(1988) [PubMed: 3143729] [Abstract]
Cited for: CHARACTERIZATION.
Tissue: Small intestine mucosa.
[6]"Tyrosine sulfation, a post-translational modification of microvillar enzymes in the small intestinal enterocyte."
Danielsen E.M.
EMBO J. 6:2891-2896(1987) [PubMed: 3121301] [Abstract]
Cited for: SULFATION.
[7]"Human intestinal maltase-glucoamylase: crystal structure of the N-terminal catalytic subunit and basis of inhibition and substrate specificity."
Sim L., Quezada-Calvillo R., Sterchi E.E., Nichols B.L., Rose D.R.
J. Mol. Biol. 375:782-792(2008) [PubMed: 18036614] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF 87-954, GLYCOSYLATION, DISULFIDE BONDS.
+Additional computationally mapped references.

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Cross-references

Sequence databases

AF016833 mRNA. Translation: AAC39568.2.
AC091684 Genomic DNA. Translation: AAP21875.1.
AC073647 Genomic DNA. Translation: AAS07445.1.
AC091742 Genomic DNA. No translation available.
BC120872 mRNA. Translation: AAI20873.1.
IPIIPI00220143.
RefSeqNP_004659.2.
UniGeneHs.122785

3D structure databases

EntryMethodResolution (Å)ChainPositionsPDBsum
2QLYX-ray2.00A87-954[»]
2QMJX-ray1.90A87-954[»]
3CTTX-ray2.10A87-954[»]
ModBaseSearch...

Protein family/group databases

CAZyGH31. Glycoside Hydrolase Family 31.

Proteomic databases

PRIDEO43451.

Genome annotation databases

EnsemblENSG00000179087. Homo sapiens. [Contig view]
GeneID8972.
KEGGhsa:8972.

Organism-specific databases

GeneCardsGC07P141342.
H-InvDBHIX0025263.
HIX0033850.
HGNCHGNC:7043. MGAM.
HPAHPA002270.
MIM154360. gene.
PharmGKBPA30778.
GenAtlasSearch...

Phylogenomic databases

HOGENOMO43451.
HOVERGENO43451.

Enzyme and pathway databases

BRENDA3.2.1.20. 247.
3.2.1.3. 247.
ReactomeREACT_474. Metabolism of carbohydrates.

Gene expression databases

ArrayExpressO43451.
BgeeO43451.
CleanExHS_MGA.
HS_MGAM.

Family and domain databases

InterProIPR000322. Glyco_hydro_31.
IPR000519. P_trefoil.
[Graphical view]
PfamPF01055. Glyco_hydro_31. 2 hits.
PF00088. Trefoil. 1 hit.
[Graphical view]
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 Resources

DrugBankDB00284. Acarbose.
DB00491. Miglitol.
DB04878. Voglibose.
NextBio33667.
SOURCESearch...

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Entry information

Entry nameMGA_HUMAN
AccessionPrimary (citable) accession number: O43451
Secondary accession number(s): Q0VAX6, Q75ME7, Q86UM5
Entry history
Integrated into UniProtKB/Swiss-Prot: May 30, 2000
Last sequence update: November 25, 2008
Last modified: June 16, 2009
This is version 87 of the entry and version 5 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation projectHPI (Human Proteome Initiative)

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Relevant documents

Glycosyl hydrolases

Classification of glycosyl hydrolase families and list of entries

Human chromosome 7

Human chromosome 7: entries, gene names and cross-references to MIM

Human entries with polymorphisms or disease mutations

List of human entries with polymorphisms or disease mutations

Human polymorphisms and disease mutations

Index of human polymorphisms and disease mutations

MIM cross-references

Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot

PDB cross-references

Index of Protein Data Bank (PDB) cross-references

SIMILARITY comments

Index of protein domains and families

Names and origin · Protein attributes · General annotation (Comments) · Ontologies · Sequence annotation (Features) · Sequences · References · Cross-references · Entry information · Relevant documents