sABO-A:Mn2+ transfers GalNAc to H antigen-sec to form A antigen-sec

Stable Identifier
Reaction [transition]
Homo sapiens
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As well as being a Golgi membrane resident, the histo-blood group ABO system transferase (ABO) can be proteolytically processed by an unknown protease into a soluble form, fucosylglycoprotein alpha-N-acetylgalactosaminyltransferase (sABO). A, B and AB individuals express glycosyltransferase activities that convert the H antigen to the A antigen (by addition of GalNAc), to the B antigen (by addition of Gal) or to the AB antigen (by the addition of both GalNAc and Gal). O group individuals lack such activity. Differences in four critical amino acids (176, 235, 266 and 268) alter the specificity from an A to a B glycosyltransferase (Yamamoto et al. 1990, Yamamoto & McNeill 1996, Seto et al. 1999, Alfaro et al. 2008). The soluble form of histo-blood group A transferase (sABO-A) utilises UDP-GalNAc to transfer N-acetylgalactosamine (GalNAc) to the H antigen formed via Type 1 chains to form the A antigen in secretors (A antigen-sec) (Patenaude et al. 2002, Persson et al. 2007).

Literature References
PubMed ID Title Journal Year
2333095 Molecular genetic basis of the histo-blood group ABO system

Marken, J, White, T, Yamamoto, F, Hakomori, S, Clausen, H

Nature 1990
18192272 ABO(H) blood group A and B glycosyltransferases recognize substrate via specific conformational changes

Seto, NO, Bai, Y, Borisova, SN, Persson, M, Alfaro, JA, Evans, SV, Polakowski, R, Letts, JA, Zheng, RB, Palcic, MM, Lowary, TL

J. Biol. Chem. 2008
8631849 Amino acid residue at codon 268 determines both activity and nucleotide-sugar donor substrate specificity of human histo-blood group A and B transferases. In vitro mutagenesis study

Yamamoto, F, McNeill, PD

J. Biol. Chem. 1996
12198488 The structural basis for specificity in human ABO(H) blood group biosynthesis

Marcus, SL, Seto, NO, Borisova, SN, Evans, SV, Patenaude, SI, Szpacenko, A, Palcic, MM

Nat. Struct. Biol. 2002
10092863 Donor substrate specificity of recombinant human blood group A, B and hybrid A/B glycosyltransferases expressed in Escherichia coli

Evans, SV, Bundle, DR, Palcic, MM, Compston, CA, Seto, NO, Narang, SA

Eur. J. Biochem. 1999
17259183 Structural effects of naturally occurring human blood group B galactosyltransferase mutations adjacent to the DXD motif

Hosseini-Maaf, B, Borisova, SN, Persson, M, Olsson, ML, Evans, SV, Letts, JA, Palcic, MM

J. Biol. Chem. 2007
Catalyst Activity

glycoprotein-fucosylgalactoside alpha-N-acetylgalactosaminyltransferase activity of sABO-A:Mn2+ [extracellular region]

Orthologous Events
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