Analysis of Saccharomyces cerevisiae histone H3 mutants reveals the role of the alphaN helix in nucleosome function.
To understand the role of histone H3 sub-domains in chromatin function, 35 histone H3 tandem alanine mutants were generated and tested for their viability and sensitivity to DNA damaging agents. Among 13 non-viable H3 mutants, 6 were mapped around the alphaN helix and preceding tail region. Mutants with individual alanine substitutions in this region were viable but developed multiple sensitivities to DNA damaging agents. The only viable triple mutant, REI49-50A, in the alphaN helix region could not grow when combined with histone chaperone mutations, such as asf1Delta, cac1Delta, or hir1Delta, suggesting that this particular region is important when the histone assembly/disassembly pathway is compromised. In addition, further analysis showed that T45, E50, or F54 of the alphaN helix genetically interacted with a histone chaperone (Asf1) and transcription elongation factors (Paf1 and Hpr1). These results suggest a specific role of the H3 alphaN helix in histone dynamics mediated by histone chaperones, which might be important during transcription elongation.
Seol
Ja-Hwan
JH
College of Pharmacy, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do 440-746, Republic of Korea.
Kim
Hye-Jin
HJ
Yoo
Ja-Kyung
JK
Park
Hyun-Ju
HJ
Cho
Eun-Jung
EJ
D000409:Alanine / Q000235:genetics / Q000378:metabolism; D000477:Alkylating Agents / Q000494:pharmacology; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D018797:Cell Cycle Proteins / Q000378:metabolism; D004252:DNA Mutational Analysis; D006657:Histones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006918:Hydroxyurea / Q000494:pharmacology; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D018832:Molecular Chaperones / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism; D009707:Nucleosomes / Q000187:drug effects / Q000378:metabolism*; D017433:Protein Structure, Secondary; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D020080:Tandem Repeat Sequences
C109731:ASF1 protein, S cerevisiae; D000477:Alkylating Agents; D018797:Cell Cycle Proteins; C063494:HPR1 protein, S cerevisiae; D006657:Histones; D018832:Molecular Chaperones; D009687:Nuclear Proteins; D009707:Nucleosomes; C097698:PAF1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D008741:Methyl Methanesulfonate; D012264:Ribonucleotide Reductases; D000409:Alanine; D006918:Hydroxyurea