High impact information on LYS9

• Here we show that trimethylated H3 Lys9, but not dimethylated H3 Lys9, marks chromatin regions for cytosine methylation and that DIM-5 specifically creates this mark [1].
• The predicted polypeptide has an N-terminal LKR domain and a C-terminal SDH domain that are similar to the yeast LYS1 and LYS9 monofunctional proteins, respectively [2].
• These cells carry elevated levels of methylated histone H3-Lys4 and reduced levels of methylated histone H3-Lys9 [3].
• We mapped pop2 to chromosome XIV, distal to lys9 and SUP28, indicating that POP2 is a newly-identified locus [4].
• This identity extends to the high-energy conformations of the active-site residues Lys13 and Ser211, as well as the positions of several bound water molecules that are retained in the active site when PGH is bound [5].

Biological context of LYS9

• The regulatory property of lys9 mutants exhibited recessiveness to the wild-type gene in heterozygous diploids [6].
• Unlike the mating type effect, homozygous diploids resulting from crosses between lys9 auxotrophs exhibited even higher levels of derepressed enzymes than the haploid mutants [6].
• Consistent with the importance of saccharopine dehydrogenase and spermidine synthase in vitro, spe3-lys9 mutants were avirulent and unable to survive in vivo and both functions individually contributed to virulence [7].

Associations of LYS9 with chemical compounds

• The synthesis of saccharopine dehydrogenase (glutamate-forming), previously shown to require the unlinked genes LYS9 and LYS14, is also affected by the induction mechanism [8].
• The leaky auxotrophic behaviour of lys14 mutants is explained by the low basal level of expression of LYS9, the structural gene of this enzyme, in the absence of induction by 2-aminoadipate semialdehyde [8].
• Two unlinked lysine genes (LYS9 and LYS14) are required for the synthesis of saccharopine reductase in Saccharomyces cerevisiae [9].
• Five enzymes (homocitrate synthase, homoisocitrate dehydrogenase, alpha-aminoadipate aminotransferase, alpha-aminoadipate reductase and saccharopine dehydrogenase) were constitutively derepressed in all lys9 mutants with up to eight-fold higher enzyme levels than in isogenic wild-type cells [6].
• Therefore, we identified and describe a novel chimeric SPE3-LYS9 gene, which may link spermidine and lysine biosynthesis in C. neoformans [7].

Other interactions of LYS9

• Novel chimeric spermidine synthase-saccharopine dehydrogenase gene (SPE3-LYS9) in the human pathogen Cryptococcus neoformans [7].
• Lys10 mutants displayed NAD-reducing activity, whereas lys9 mutants retained some carboxylating activity [10].
• A DNA fragment complementing the 10.25 mutation has been cloned; sequence analysis of the cloned gene (named lys7) revealed that it encoded a protein with high similarity to the saccharopine reductase from Neurospora crassa, Magnaporthe grisea, Saccharomyces cerevisiae, and Schizosaccharomyces pombe [11].
• The pet494-1 mutation maps to chromosome XIV between rna2 and lys9, approximately 2.4 cm from lys9 [12].

References