Residues in the Nucleosome Acidic Patch Regulate Histone Occupancy and Are Important for FACT Binding in Saccharomyces cerevisiae

• Published in: Genetics (Austin) 2017-07, Vol.206 (3), p.1339-1348
• Main Authors: Hodges, Amelia J, Gloss, Lisa M, Wyrick, John J
• Format: Article
• Language: English
• Subjects: Baking yeast; Binding; Binding Sites; Chromatin; Deletion mutant; Deoxyribonucleic acid; Dimers; DNA; DNA biosynthesis; DNA methylation; DNA repair; Genetics; Histone H2A; Histones - genetics; Histones - metabolism; In vitro methods and tests; Investigations; Mutants; Mutation; Nucleosome Assembly Protein 1 - genetics; Nucleosome Assembly Protein 1 - metabolism; Nucleosomes; Nucleosomes - chemistry; Nucleosomes - genetics; Nucleosomes - metabolism; Plasmids; Protein Binding; Proteins; Residues; RNA polymerase; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Transcription; Transcription Factors - genetics; Transcription Factors - metabolism; Transcriptional Elongation Factors - genetics; Transcriptional Elongation Factors - metabolism; Yeast
• ISSN: 1943-2631; 0016-6731; 1943-2631
• DOI: 10.1534/genetics.117.201939

The essential histone chaperone FACT plays a critical role in DNA replication, repair, and transcription, primarily by binding to histone H2A-H2B dimers and regulating their assembly into nucleosomes. While FACT histone chaperone activity has been extensively studied, the exact nature of the H2A and H2B residues important for FACT binding remains controversial. In this study, we characterized the functions of residues in the histone H2A and H2B acidic patch, which is important for binding many chromatin-associated factors. We found that mutations in essential acidic patch residues cause a defect in histone occupancy in yeast, even though most of these histone mutants are expressed normally in yeast and form stable nucleosomes Instead, we show that two acidic patch residues, H2B L109 and H2A E57, are important for histone binding to FACT We systematically screened mutants in other H2A and H2B residues previously suspected to be important for FACT binding and confirmed the importance of H2B M62 using an FACT-binding assay. Furthermore, we show that, like deletion mutants in FACT subunits, an H2A E57 and H2B M62 double mutant is lethal in yeast. In summary, we show that residues in the nucleosome acidic patch promote histone occupancy and are important for FACT binding to H2A-H2B dimers in yeast.