Joanin P, Gigot C, Philipps G
Institut de Biologie Moléculaire des Plantes du C.N.R.S., Université Louis Pasteur, Strasbourg, France.
Plant Mol Biol. 1992 Nov;20(4):581-8. doi: 10.1007/BF00046443.
The complete amino acid sequences of two variants of histone H2B of maize were deduced from the cDNAs isolated from a maize cDNA library. The two encoded proteins are 150 (H2B(1)) and 149 (H2B(2)) amino acids long and shows the classical organization of H2B histones. The hydrophobic C-terminal region is highly conserved as compared to that of the animal counterparts with only 21 changes (13 conservative) among the 90 residues. Between the N-terminal part and the C-terminal region we note the presence of a basic cluster (9 residues) characteristic of histones H2B. The N-terminal third is extended as compared to the animal consensus H2B and has the same size as the H2B histone of wheat. Up to 9 acidic residues and a five time repeated pentapeptide PA/KXE/KK are present in this region. Southern-blot hybridization showed that the H2B histones are encoded by a multigenic family like the other core histones (H3 and H4) of plants. The general expression pattern of these genes was not significantly different from that of the H3 and H4 genes neither in germinating seeds nor in different tissues of adult maize.
从玉米cDNA文库中分离出的cDNA推导得出了玉米组蛋白H2B的两种变体的完整氨基酸序列。这两种编码蛋白分别由150个（H2B(1)）和149个（H2B(2)）氨基酸组成，呈现出H2B组蛋白的经典结构。与动物对应物相比，其疏水的C末端区域高度保守，在90个残基中仅有21处变化（13处保守变化）。在N末端部分和C末端区域之间，我们注意到存在一个组蛋白H2B特有的碱性簇（9个残基）。与动物的共有H2B相比，N末端的三分之一区域有所延长，且与小麦的H2B组蛋白大小相同。该区域存在多达9个酸性残基以及一个重复五次的五肽PA/KXE/KK。Southern杂交显示，H2B组蛋白与植物的其他核心组蛋白（H3和H4）一样，由一个多基因家族编码。这些基因在萌发种子和成年玉米的不同组织中的总体表达模式与H3和H4基因的表达模式没有显著差异。
