TABLE 2

Summary of phenotypes observed for indicated histone alleles

PhenotypesaH2A allelesH2B alleles
Loss of telomeric silencing (LTS)R18AR75A; R75K; R75L; R75M; K89A; R95A; R95K; K111Q; R119K; K123A; K123R; K123Q
Increase of telomeric silencing (ITS)R102A; R102K
Loss of rDNA silencing (LRS)K21A; R75A; R102A; R102K; K111R; R119K; K123A; K123R; K123Q
Increase of rDNA silencing (IRS)R18A; R36A; K75R; R78K; K96A; K119QK6Q; K11A; K11Q; K16A; K16Q; K34A; K34Q; K46A; K46Q; K89A; K89R; K89Q; R95A; R95K
Sensitive to HUK76A; K76Q; R78A111Q; K123A; K123R; K123Q
Sensitive to MMSR18A; K76A; K76Q; R78A
Sensitive to CPTR78A
Temperature sensitivity (39°)R18A; K76A; K76Q; R78A; R78KR95A; R102K; R119K; K123A; K123R; K123Q
  • Residues covered in this test include H2A: K4, K7, K13, R18, R36, K75, K76, R78, K96, K119, K123, K126 and H2B: K3, K6, K11, K16, K21, K22, K34, K46, R75, K88, K89, R95, R102, K111, R119, K123. Each lysine was mutated to alanine, arginine, and glutamine and each arginine was mutated to lysine and glutamine. H2B K75 was also mutated to leucine and methionine. The mutants were analyzed and their phenotypes were compared to wild type and scored arbitrarily.

  • a Other phenotypes tested include sensitivity to 6-azauracil (6-AU), benomyl, UV irradiation, and temperature sensitivity at 37° and 16°, which none of the mutants have.