SAM1/YLR180W Summary Help

Standard Name SAM1 1
Systematic Name YLR180W
Alias ETH10
Feature Type ORF, Verified
Description S-adenosylmethionine synthetase; catalyzes transfer of the adenosyl group of ATP to the sulfur atom of methionine; SAM1 has a paralog, SAM2, that arose from the whole genome duplication (2, 3, 4, 5 and see Summary Paragraph)
Name Description S-AdenosylMethionine requiring 6
Chromosomal Location
ChrXII:515262 to 516410 | ORF Map | GBrowse
Gene Ontology Annotations All SAM1 GO evidence and references
  View Computational GO annotations for SAM1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Regulators 13 genes
Classical genetics
Large-scale survey
179 total interaction(s) for 127 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 110
  • Affinity Capture-RNA: 6
  • Co-fractionation: 1
  • Co-purification: 1
  • PCA: 1
  • Protein-RNA: 1
  • Two-hybrid: 2

Genetic Interactions
  • Dosage Growth Defect: 1
  • Dosage Rescue: 1
  • Negative Genetic: 28
  • Phenotypic Enhancement: 6
  • Phenotypic Suppression: 1
  • Positive Genetic: 9
  • Synthetic Growth Defect: 6
  • Synthetic Lethality: 4
  • Synthetic Rescue: 1

Expression Summary
Length (a.a.) 382
Molecular Weight (Da) 41,818
Isoelectric Point (pI) 4.91
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXII:515262 to 516410 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1149 515262..516410 2011-02-03 1996-07-31
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 SGDIDS000004170

SAM1 and SAM2 encode S-adenosylmethionine (AdoMet) synthetases (also known as methionine adenosyl transferases (MAT)), which catalyze the biosynthesis of AdoMet from methionine and ATP (6). AdoMet is involved in the methylation of proteins, RNAs, and lipids (7) as well as in the biosynthesis of biotin (8) and polyamines (9, 10). AdoMet is believed to participate in more reactions than any other cofactor with the exception of ATP (7).

Mutations in SAM1 or SAM2 do not affect growth; however, a sam1 sam2 double mutant results in AdoMet auxotrophy (6). Although SAM1 and SAM2 encode functionally equlvalent AdoMet synthetases, they are regulated differently (2). Both SAM1 and SAM2 are repressed by excess AdoMet, but expression of SAM2 increases during growth, which overrides the AdoMet-mediated repression (2). In addition, SAM2 is repressed by the addition of myo-inositol and choline, similar to a number of genes encoding enzymes involved in phospholipid biosynthesis (4). In contrast, SAM1 is not subject to the inositol-choline regulation suggesting that SAM2, but not SAM1, may be involved in phospholipid biosynthesis (4).

AdoMet synthetase is well conserved through evolution (from 2). In humans, deficiency in AdoMet synthetase results in the metabolic disease, hypermethioninemia (OMIM)(11).

Last updated: 2009-02-26 Contact SGD

References cited on this page View Complete Literature Guide for SAM1
1) Rosenberg, N. and Rothstein, R.  (1992) Personal Communication, Mortimer Map Edition 11
2) Thomas D and Surdin-Kerjan Y  (1991) The synthesis of the two S-adenosyl-methionine synthetases is differently regulated in Saccharomyces cerevisiae. Mol Gen Genet 226(1-2):224-32
3) Thomas D and Surdin-Kerjan Y  (1987) SAM1, the structural gene for one of the S-adenosylmethionine synthetases in Saccharomyces cerevisiae. Sequence and expression. J Biol Chem 262(34):16704-9
4) Kodaki T, et al.  (2003) Differential transcriptional regulation of two distinct S-adenosylmethionine synthetase genes (SAM1 and SAM2) of Saccharomyces cerevisiae. Nucleic Acids Res Suppl (3):303-4
5) Byrne KP and Wolfe KH  (2005) The Yeast Gene Order Browser: combining curated homology and syntenic context reveals gene fate in polyploid species. Genome Res 15(10):1456-61
6) Cherest H and Surdin-Kerjan Y  (1978) S-adenosyl methionine requiring mutants in Saccharomyces cerevisiae: evidences for the existence of two methionine adenosyl transferases. Mol Gen Genet 163(2):153-67
7) Thomas D and Surdin-Kerjan Y  (1997) Metabolism of sulfur amino acids in Saccharomyces cerevisiae. Microbiol Mol Biol Rev 61(4):503-32
8) Phalip V, et al.  (1999) Characterization of the biotin biosynthesis pathway in Saccharomyces cerevisiae and evidence for a cluster containing BIO5, a novel gene involved in vitamer uptake. Gene 232(1):43-51
9) Chattopadhyay MK, et al.  (2006) Methylthioadenosine and polyamine biosynthesis in a Saccharomyces cerevisiae meu1delta mutant. Biochem Biophys Res Commun 343(1):203-7
10) Subhi AL, et al.  (2003) Methylthioadenosine phosphorylase regulates ornithine decarboxylase by production of downstream metabolites. J Biol Chem 278(50):49868-73
11) Foury F  (1997) Human genetic diseases: a cross-talk between man and yeast. Gene 195(1):1-10