Disease relevance of SAM2

• In addition a recombinant strain of E. coli has been constructed that expresses the yeast SAM synthetase encoded by the sam2 gene [1].

High impact information on SAM2

• The activation region contained a repeated dyad sequence that is also found in the promoter regions of other unlinked but coordinately regulated genes (MET3, MET2, and SAM2) [2].
• The results show that the expression of the two SAM genes is regulated differently, SAM2 being induced by the presence of excess methionine in the growth medium and SAM1 being repressed under the same conditions [3].
• SAM2 encodes the second methionine S-adenosyl transferase in Saccharomyces cerevisiae: physiology and regulation of both enzymes [3].
• SAM1 and SAM2, located on chromosomes XII and IV, respectively, encode functionally equivalent although differentially regulated AdoMet synthetases [4].
• Single frameshift mutations were introduced into the 5' end of SAM1 and the 3' end of SAM2 by restriction site ablation [4].

Biological context of SAM2

• Null mutations in three recombination and DNA repair genes were studied to determine their effects on mitotic recombination between the duplicate AdoMet (S-adenosylmethionine) synthetase genes (SAM1 and SAM2) in Saccharomyces cerevisiae [4].
• The deduced amino acid sequence of rat liver S-adenosylmethionine synthetase was 68% similar to those of yeast S-adenosylmethionine synthetases encoded by two unlinked genes SAM1 and SAM2 [5].
• A study of in vivo and in vitro methylation of tRNAs in regulatory mutants affected in methionine-mediated repression (eth2, eth3, eth10) has led to the following results: 1) The eth2-2 carrying strain presents a great undermethylation of its tRNAs of the same order of magnitude as observed during methionine starvation of methionine auxotrophs [6].

Other interactions of SAM2

• Mutations at the SAM1 locus lead to the absence or to the modification of MATII whereas mutations at the SAM2 locus lead to the absence or to the modification of MATI [7].
• Clones corresponding to isogenes SAM2 and SAM3 have also been isolated and sequenced [8].

References