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MetaCyc Enzyme: mannosyltransferase

Gene: ALG9 Accession Number: G-5582 (MetaCyc)

Synonyms: Alg9p

Species: Saccharomyces cerevisiae

Summary:
Sequence analysis predicted that ALG9 encodes a protein with a cleavable signal sequence at the N-terminus. It appeared to be a hydrophobic protein with a hydrophilic C-terminal domain, and 4 potential N-linked glycosylation sites. An endoplasmic reticulum location was also suggested by these analyses [Burda96].
ALG9 mutants accumulate (mannosyl)6-(N-acetylglucosaminyl)2-diphosphodolichol [Burda96, Cipollo00].

Gene Citations: [Frank05]

Locations: endoplasmic reticulum

Map Position: [235,995 <- 237,662]

Molecular Weight of Polypeptide: 63.8 kD (from nucleotide sequence)

Unification Links: DIP:DIP-4288N , Entrez-gene:855502 , Mint:MINT-507147 , ModBase:P53868 , Protein Model Portal:P53868 , String:4932.YNL219C , Swiss-Model:P53868 , UniProt:P53868

Relationship Links: CAZy:IN-FAMILY:GT22 , InterPro:IN-FAMILY:IPR005599 , Panther:IN-FAMILY:PTHR22760 , Pfam:IN-FAMILY:PF03901

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Cellular Component: GO:0005783 - endoplasmic reticulum [Burda96]

Credits:
Revised 25-Sep-2006 by Fulcher CA , SRI International


Enzymatic reaction of: (mannosyl)8-(N-acetylglucosaminyl)2-diphosphodolichol:dolichyl β-D-mannosyl phosphate mannosyl transferase (mannosyltransferase)

EC Number: 2.4.1.261

a (mannosyl)8-(N-acetylglucosaminyl)2-diphosphodolichol + a dolichyl β-D-mannosyl phosphate <=> a (mannosyl)9-(N-acetylglucosaminyl)2-diphosphodolichol + a dolichyl phosphate + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: dolichyl-diphosphooligosaccharide biosynthesis

Summary:
The Alg9 gene product is involved in the addition of the seventh and ninth mannose to the lipid-linked oligosaccharide chain [Frank05].


Enzymatic reaction of: (mannosyl)6-(N-acetylglucosaminyl)2-diphosphodolichol:dolichyl β-D-mannosyl phosphate mannosyl transferase (mannosyltransferase)

EC Number: 2.4.1.259

a (mannosyl)6-(N-acetylglucosaminyl)2-diphosphodolichol + a dolichyl β-D-mannosyl phosphate <=> a (mannosyl)7-(N-acetylglucosaminyl)2-diphosphodolichol + a dolichyl phosphate + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: dolichyl-diphosphooligosaccharide biosynthesis

Summary:
ALG9 mutants accumulate (mannosyl)6-(N-acetylglucosaminyl)2-diphosphodolichol [Cipollo00, Burda96].

The Alg9 gene product is involved in the addition of the seventh and ninth mannose to the lipid-linked oligosaccharide chain [Frank05].

Citations: [Cipollo01]


References

Burda96: Burda P, te Heesen S, Brachat A, Wach A, Dusterhoft A, Aebi M (1996). "Stepwise assembly of the lipid-linked oligosaccharide in the endoplasmic reticulum of Saccharomyces cerevisiae: identification of the ALG9 gene encoding a putative mannosyl transferase." Proc Natl Acad Sci U S A 93(14);7160-5. PMID: 8692962

Cipollo00: Cipollo JF, Trimble RB (2000). "The accumulation of Man(6)GlcNAc(2)-PP-dolichol in the Saccharomyces cerevisiae Deltaalg9 mutant reveals a regulatory role for the Alg3p alpha1,3-Man middle-arm addition in downstream oligosaccharide-lipid and glycoprotein glycan processing." J Biol Chem 275(6);4267-77. PMID: 10660594

Cipollo01: Cipollo JF, Trimble RB, Chi JH, Yan Q, Dean N (2001). "The yeast ALG11 gene specifies addition of the terminal alpha 1,2-Man to the Man5GlcNAc2-PP-dolichol N-glycosylation intermediate formed on the cytosolic side of the endoplasmic reticulum." J Biol Chem 276(24);21828-40. PMID: 11278778

Frank05: Frank CG, Aebi M (2005). "ALG9 mannosyltransferase is involved in two different steps of lipid-linked oligosaccharide biosynthesis." Glycobiology 15(11);1156-63. PMID: 15987956


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Fri May 22, 2015, BIOCYC14A.