Hayashi T, Hayashi H, Fusauchi Y, Iwai K
J Biochem. 1984 Jun;95(6):1741-9. doi: 10.1093/oxfordjournals.jbchem.a134788.
The H3 histone of the protozoan Tetrahymena pyriformis was obtained as described previously (Fusauchi, Y. & Iwai, K. (1983) J. Biochem. 93, 1487-1497) and further purified by Sephadex G-50 chromatography after reduction and carboxymethylation. The purified H3 was shown to comprise two variants, 75 mol% of H3(1) and 25 mol% of H3(2). The H3 mixture was directly sequenced by Edman degradation from the N-terminal through residue 104. Sequence determination was further performed with tryptic peptides and cyanogen bromide fragments derived from the H3 mixture. Thus, the total sequences of H3(1) and H3(2) were completely determined; both consist of a total of 135 amino acid residues (the molecular weights in the unmodified form are 15,336 for H3(1) and 15,424 for H3(2), and both are partially acetylated or methylated at the same six lysine residues to similar extents. The H3(1) and H3(2) sequences differ in 14 positions from each other, and in 17 and 21 positions from those of human spleen H3 (Ohe, Y. & Iwai, K. (1981) J. Biochem. 90, 1205-1211). The implications of these results for the structure-function relationship of this histone species and also for the phylogeny of protozoa are discussed.
梨形四膜虫的H3组蛋白如前所述获得（Fusauchi, Y. & Iwai, K. (1983) J. Biochem. 93, 1487 - 1497），在还原和羧甲基化后通过Sephadex G - 50柱色谱进一步纯化。纯化后的H3显示由两种变体组成，75摩尔%的H3(1)和25摩尔%的H3(2)。H3混合物通过埃德曼降解从N端直接测序至第104位残基。对源自H3混合物的胰蛋白酶肽段和溴化氰片段进一步进行序列测定。因此，H3(1)和H3(2)的完整序列得以完全确定；两者均由总共135个氨基酸残基组成（未修饰形式下H3(1)的分子量为15,336，H3(2)的分子量为15,424，且两者在相同的六个赖氨酸残基处均有部分乙酰化或甲基化，程度相似。H3(1)和H3(2)的序列在14个位置上彼此不同，与人类脾脏H3的序列在17个和21个位置上不同（Ohe, Y. & Iwai, K. (1981) J. Biochem. 90, 1205 - 1211）。讨论了这些结果对该组蛋白物种的结构 - 功能关系以及对原生动物系统发育的意义。
