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同源结构域是一个保守的DNA结合区,特异地存在于从线虫到人类的发育调节蛋白中。从其一至三级结构和与DNA相互作用的模式中发现,在进化过程中它具有高度保守性。其60个氨基酸残基可形成3个α-螺旋和一个延伸的N-末端氨基酸臂。大部分同源结构域序列高度保守,构成一致性序列,具有促进其形成三级结构和调节DNA结合的能力。α-螺旋Ⅰ—Ⅲ区内的一致性序列构建了一个亲水核,保存其α-螺旋亲水与疏水的两性特征,而螺旋Ⅲ及N-末端氨基酸臂序列则与DNA接触。尽管同源结构域存在广泛的序列保守性,但含同源结构域的蛋白质仍然有其各自的功能,对此目前尚无恰当的解释。为此,作者以Msx-1蛋白质的同源结构域
A homologous domain is a conserved DNA binding region that is specifically found in nematodes to human developmental regulatory proteins. From its primary to tertiary structure and its interaction with DNA, it is found to be highly conserved during evolution. Its 60 amino acid residues form 3 alpha-helices and an extended N-terminal amino acid arm. Most homologous domain sequences are highly conserved and form conformable sequences with the ability to promote their formation of tertiary structures and to regulate DNA binding. The consensus sequence in the α-helix Ⅰ-Ⅲ region constructs a hydrophilic nucleus that retains both the hydrophilic and hydrophobic amphipathic features of the α-helix, while the helix Ⅲ and N-terminal amino acid arm sequences are in contact with the DNA. Although homologous domains have a wide range of sequence conservation, homologous domain-containing proteins still have their own functions, so far there is no proper explanation for this. To this end, the authors use the homologous domain of the Msx-1 protein