Laine B, Kmiecik D, Sautiere P, Biserte G, Cohen-Solal M
Eur J Biochem. 1980 Feb;103(3):447-61. doi: 10.1111/j.1432-1033.1980.tb05968.x.
The DNA-binding protein HU from Escherichia coli is a heterodimer constituted of two polypeptide chains termed HU-1 and HU-2, of 90 residues each. Their primary structures were established from structural data obtained from tryptic peptides of each monomer in addition to the structural data provided by the automated Edman degradation of the dimer and by peptides derived from cleavage of the dimer with trypsin, chymotrypsin, V8 staphylococcal protease and dilute acid. The results presented in this paper confirm the amino-terminal and carboxy-terminal sequences of the dimer HU reported previously [Laine et al. (1978) FEBS Lett. 89, 116--120]. The amino acid sequences of proteins HU-1 and HU-2 are identical to those of proteins NS-1 and NS-2 respectively, determined independently by Mende et al. [FEBS Lett. (1978) 96, 395--398]. The amino acid sequences of proteins HU-1 and HU-2 are closely related but differ by 28 residues. These proteins are characterized by their high content of hydrophobic residues represented mostly by alanine. In both proteins, half of the basic residues are scattered along the polypeptide chain and the remainder is found within two short sequences located in the carboxy-terminal part of the molecule. No sequence homology could be established between the proteins HU-1 and HU-2 and any one of the five histones from different eukaryotes.
来自大肠杆菌的DNA结合蛋白HU是一种异源二聚体，由两条分别含90个残基的多肽链HU-1和HU-2组成。除了通过二聚体的自动埃德曼降解以及用胰蛋白酶、胰凝乳蛋白酶、V8葡萄球菌蛋白酶和稀酸切割二聚体得到的肽段所提供的结构数据外，还根据每个单体的胰蛋白酶肽段获得的结构数据确定了它们的一级结构。本文给出的结果证实了先前报道的二聚体HU的氨基末端和羧基末端序列[莱恩等人（1978年）《欧洲生物化学学会联合会快报》89卷，116 - 120页]。蛋白质HU-1和HU-2的氨基酸序列分别与门德等人独立确定的蛋白质NS-1和NS-2的氨基酸序列相同[《欧洲生物化学学会联合会快报》（1978年）96卷，395 - 398页]。蛋白质HU-1和HU-2的氨基酸序列密切相关，但相差28个残基。这些蛋白质的特征在于其高含量的疏水残基，主要由丙氨酸代表。在这两种蛋白质中，一半的碱性残基沿多肽链分散，其余的位于分子羧基末端部分的两个短序列内。在蛋白质HU-1和HU-2与来自不同真核生物的五种组蛋白中的任何一种之间都无法建立序列同源性。
