Missing parent: GO:0004583 dolichyl-phosphate-glucose-glycolipid alpha-glucosyltransferase activity subclasses

[ValWood]

• GO term ID and label for which you request a new superclass

It seems that, based on definition and annotations

GO:0106073 dolichyl pyrophosphate Glc2Man9GlcNAc2 alpha-1,2-glucosyltransferase activity Catalysis of the addition of the third glucose residue to the lipid-linked oligosaccharide precursor for N-linked glycosylation; the transfer of glucose from dolichyl phosphate glucose (Dol-P-Glc) on to the lipid-linked oligosaccharide Glc(2)Man(9)GlcNAc(2)-PP-Dol. PMID:9597543

and

GO:0042281 | dolichyl pyrophosphate Man9GlcNAc2 alpha-1,3-glucosyltransferase activity Catalysis of the addition of the first glucose residue to the lipid-linked oligosaccharide precursor for N-linked glycosylation; the transfer of glucose from dolichyl phosphate glucose (Dol-P-Glc) on to the lipid-linked oligosaccharide Man(9)GlcNAc(2)-PP-Dol.

and

GO:0042283 | dolichyl pyrophosphate Glc1Man9GlcNAc2 alpha-1,3-glucosyltransferase activity Catalysis of the addition of the second glucose residue to the lipid-linked oligosaccharide precursor for N-linked glycosylation; the transfer of glucose from dolichyl phosphate glucose (Dol-P-Glc) on to the lipid-linked oligosaccharide Glc(1)Man(9)GlcNAc(2)-PP-Dol. [PMID:12480927]

should be is_a GO:0004583 dolichyl-phosphate-glucose-glycolipid alpha-glucosyltransferase activity Catalysis of the transfer of an alpha-D-glucosyl residue from dolichyl-phosphate D-glucose into a membrane lipid-linked oligosaccharide.

• New superclass (parent) suggested

• Reference(s), if appropriate PMID:nnnnnnn

[pgaudet]

Feedback from Ben Kellman (expect contacted by Frederique Lisacek):

I am not an experienced curator, so I can't comment with certainty on the meaning of parentage. However, I have spent time in glycan biosynthesis, so I may be of help there.

Since you work in yeast, you are likely aware of ALG genes. For citations, PMID:11425794 provides some useful citations in the broader context of Dolichol-P-P-GlcNAc2Man9Glc3 biosynthesis. The final paragraph references the yeast knockouts that uncovered the alg genes responsible for the process.

Here is a more modern figure summarizing the process and context:

Essentials of Glycobiology [Internet]. 4th edition. Cold Spring Harbor (NY)

I'm pointing at the whole process because when I think of the dolichol-P-glycan precursor to N-glycosylation, I rarely think specifically of the terminal tri-glucose additions. Over a dozen enzymes are responsible for building N-glycan precursor. That said, these three enzymes are similar in that they share a precursor, glucose.

In summary, I think your proposal makes sense due to the similarity of these reactions. And, provided some structure already exists surrounding the context of these three reactions. E.g.: N-glycan biosynthesis N-glycan precursor biosynthesis dol-P synthesis cytosolic glcnac additions DPAGT1, 13/14 mannose additions ALG1, 2, 2, 11, 11 in ER flip dol-PP-glycan into ER mannose additions ALG3, ALG9, ALG12, ALG9 glucose additions ALG6, ALG8, ALG10 dolichol to protein transfer ....

Hope this is helpful, Ben

[kiyoko]

I agree with the suggestion to create a new superclass for these three genes.

[ValWood]

Thanks both I will add!