PMID:23469257

Citation	Williamson, K, Schneider, V, Jordan, RA, Mueller, JE, Henderson Pozzi, M and Bryk, M (2013) Catalytic and functional roles of conserved amino acids in the SET domain of the S. cerevisiae lysine methyltransferase Set1. PLoS ONE 8:e57974
Abstract	In S. cerevisiae, the lysine methyltransferase Set1 is a member of the multiprotein complex COMPASS. Set1 catalyzes mono-, di- and trimethylation of the fourth residue, lysine 4, of histone H3 using methyl groups from S-adenosylmethionine, and requires a subset of COMPASS proteins for this activity. The methylation activity of COMPASS regulates gene expression and chromosome segregation in vivo. To improve understanding of the catalytic mechanism of Set1, single amino acid substitutions were made within the SET domain. These Set1 mutants were evaluated in vivo by determining the levels of K4-methylated H3, assaying the strength of gene silencing at the rDNA and using a genetic assessment of kinetochore function as a proxy for defects in Dam1 methylation. The findings indicate that no single conserved active site base is required for H3K4 methylation by Set1. Instead, our data suggest that a number of aromatic residues in the SET domain contribute to the formation of an active site that facilitates substrate binding and dictates product specificity. Further, the results suggest that the attributes of Set1 required for trimethylation of histone H3 are those required for Pol II gene silencing at the rDNA and kinetochore function.
Links	PubMed PMC3585878 Online version:10.1371/journal.pone.0057974
Keywords	Amino Acid Sequence; Amino Acid Substitution; Catalytic Domain; Cell Cycle Proteins/genetics; Cell Cycle Proteins/metabolism; Conserved Sequence; DNA, Ribosomal/genetics; DNA, Ribosomal/metabolism; Gene Expression Regulation, Fungal; Gene Silencing; Histone-Lysine N-Methyltransferase/antagonists & inhibitors; Histone-Lysine N-Methyltransferase/genetics; Histone-Lysine N-Methyltransferase/metabolism; Histones/genetics; Histones/metabolism; Kinetochores/pathology; Lysine/metabolism; Microtubule-Associated Proteins/genetics; Microtubule-Associated Proteins/metabolism; Molecular Sequence Data; Mutation; RNA, Small Interfering/genetics; S-Adenosylmethionine/metabolism; Saccharomyces cerevisiae/enzymology; Saccharomyces cerevisiae/genetics; Saccharomyces cerevisiae Proteins/antagonists & inhibitors; Saccharomyces cerevisiae Proteins/genetics; Saccharomyces cerevisiae Proteins/metabolism; Sequence Alignment; Substrate Specificity
edit table

Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
YEAST:SET1	involved_in	GO:0044648: histone H3-K4 dimethylation	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete
YEAST:SET1	involved_in	GO:0080182: histone H3-K4 trimethylation	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete
YEAST:SET1		GO:0080182: histone H3-K4 trimethylation	ECO:0000315:		P		Figure 3. Shows a Western blot, in which it shows wild-type SET1 has H3K4 trimethylating abilities.	complete CACAO 10390
YEAST:SET1		GO:0044648: histone H3-K4 dimethylation	ECO:0000315:		P		The Western Blot in Figure 3. Shows wild-type SET1 has H3K4 dimethylating abilities.	complete CACAO 10391
YEAST:SET1		GO:0097692: histone H3-K4 monomethylation	ECO:0000315:		P		Fig. 3 shows that S. cerevisiae cells with the wild type set1 gene produce monomethylated H3K4 complexes while some of the amino acid substitution mutants do not produces these monomethylated complexes.	complete CACAO 13329
YEAST:SET1		GO:0000183: chromatin silencing at rDNA	ECO:0000315:		P		Fig. 4 shows that S. cerevisiae containing the set1 gene (labeled SET1+::ura3-52) silences rDNA transcription while the mutant lacking the set1 gene does not.	complete CACAO 13331
YEAST:SET1		GO:0006479: protein methylation	ECO:0000315:		P		Fig. 5 shows that S. cerevisiae containing a functional set1 gene (labeled SET1+) demonstrates limited growth at 30 degrees Celsius, while the colonies lacking the set1 gene show more growth at 30 degrees Celsius. Limited growth at 30 degrees indicates that methylation has not occured, while increased growth indicates a lack of methylation. “Deletion of SET1 suppresses the temperature-sensitive growth defect of cells carrying a conditional allele of the Aurora kinase, ipl1-2. Previous work has shown that this suppression is due to reduced methylation of Dam1 in the absence of Set1 [41].”	complete CACAO 13333

References

See Help:References for how to manage references in GONUTS.