Histone trimethylation by Set1 is coordinated by the RRM, autoinhibitory, and catalytic domains.

ABSTRACT: Trimethylation of lysine 4 of histone H3 occurs at the 5' end of active genes and is catalyzed by Set1 in Saccharomyces cerevisiae. Trimethylation requires histone H2B ubiquitylation and the PAF1 complex, which are linked to transcription elongation, but how they activate Set1 is not known. Set1 also bears several conserved domains with uncharacterized contributions to activity. Here, we isolated dominant hyperactive SET1(D) alleles, which revealed a complex interplay among Set1 regulatory domains. Remarkably, the RNA-recognition motif (RRM) of Set1 is required for H3K4 trimethylation, but not dimethylation. Also, a central autoinhibitory domain was identified that opposes RRM function by inhibiting trimethylation. Furthermore, a G990E replacement in the catalytic domain conferred Set1 hyp

SUBMITTER: Schlichter A 

PROVIDER: S-EPMC556409 | biostudies-literature | 2005 Mar

REPOSITORIES: biostudies-literature