ALG1/YBR110W Summary Help

Standard Name ALG1 1
Systematic Name YBR110W
Feature Type ORF, Verified
Description Mannosyltransferase; involved in asparagine-linked glycosylation in the endoplasmic reticulum (ER); essential for viability, mutation is functionally complemented by human ortholog (2, 3 and see Summary Paragraph)
Name Description Asparagine-Linked Glycosylation 1
Chromosomal Location
ChrII:458872 to 460221 | ORF Map | GBrowse
Genetic position: 54 cM
Gene Ontology Annotations All ALG1 GO evidence and references
  View Computational GO annotations for ALG1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 2 genes
Classical genetics
Large-scale survey
reduction of function
99 total interaction(s) for 93 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 3
  • Affinity Capture-Western: 3
  • PCA: 33

Genetic Interactions
  • Dosage Rescue: 1
  • Negative Genetic: 52
  • Phenotypic Enhancement: 2
  • Synthetic Growth Defect: 2
  • Synthetic Lethality: 3

Expression Summary
Length (a.a.) 449
Molecular Weight (Da) 51,929
Isoelectric Point (pI) 9.31
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrII:458872 to 460221 | ORF Map | GBrowse
Genetic position: 54 cM
Last Update Coordinates: 2011-02-03 | Sequence: 1997-01-28
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1350 458872..460221 2011-02-03 1997-01-28
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000000314

During N-linked glycosylation of proteins, oligosaccharide chains are assembled on the carrier molecule dolichyl pyrophosphate in the following order: 2 molecules of N-acetylglucosamine (GlcNAc), 9 molecules of mannose, and 3 molecules of glucose. These 14-residue oligosaccharide cores are then transferred to asparagine residues on nascent polypeptide chains in the endoplasmic reticulum (ER). As proteins progress through the Golgi apparatus, the oligosaccharide cores are modified by trimming and extension to generate a diverse array of glycosylated proteins (reviewed in 4, 5).

Alg1p, which is a beta 1,4 mannosyltransferase, catalyzes the addition of the first mannose moiety to the growing lipid-linked oligosaccharide (LLO) (1, 6) on the cytosolic side of the endoplasmic reticulum. Mutants cannot add mannose to Dol-PP-GlcNAc2, but are able to convert Man1-Dol-PP-GlcNAc2 to Man5-Dol-PP-GlcNAc2 (1). Alg1p forms two different multimeric complexes, one with Alg2p and the other with Alg11p (7).

Alg1p is homologous to Dictyostelium discoideum MntAp (8). Human ALG1 (OMIM), also known as mannosyltransferase I, complements the yeast alg1-1 mutation (9, 10) and has been found to be mutated in the congenital disorder of glycosylation CDG-1k (OMIM) (9, 10).

Last updated: 2005-07-01 Contact SGD

References cited on this page View Complete Literature Guide for ALG1
1) Huffaker TC and Robbins PW  (1982) Temperature-sensitive yeast mutants deficient in asparagine-linked glycosylation. J Biol Chem 257(6):3203-10
2) Albright CF and Robbins RW  (1990) The sequence and transcript heterogeneity of the yeast gene ALG1, an essential mannosyltransferase involved in N-glycosylation. J Biol Chem 265(12):7042-9
3) Takahashi T, et al.  (2000) Cloning of the human cDNA which can complement the defect of the yeast mannosyltransferase I-deficient mutant alg 1. Glycobiology 10(3):321-7
4) Herscovics A and Orlean P  (1993) Glycoprotein biosynthesis in yeast. FASEB J 7(6):540-50
5) Burda P and Aebi M  (1999) The dolichol pathway of N-linked glycosylation. Biochim Biophys Acta 1426(2):239-57
6) Couto JR, et al.  (1984) Cloning and expression in Escherichia coli of a yeast mannosyltransferase from the asparagine-linked glycosylation pathway. J Biol Chem 259(1):378-82
7) Gao XD, et al.  (2004) Physical interactions between the Alg1, Alg2, and Alg11 mannosyltransferases of the endoplasmic reticulum. Glycobiology 14(6):559-70
8) Lee SK, et al.  (1997) The Dictyostelium discoideum beta-1,4-mannosyltransferase gene, mntA, has two periods of developmental expression. Gene 204(1-2):251-8
9) Grubenmann CE, et al.  (2004) Deficiency of the first mannosylation step in the N-glycosylation pathway causes congenital disorder of glycosylation type Ik. Hum Mol Genet 13(5):535-42
10) Schwarz M, et al.  (2004) Deficiency of GDP-Man:GlcNAc2-PP-dolichol mannosyltransferase causes congenital disorder of glycosylation type Ik. Am J Hum Genet 74(3):472-81