Sea urchin metallothionein sequence: key to an evolutionary diversity.
Sea urchin metallothionein sequence: key to an evolutionary diversity.
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DOI：
10.1073/pnas.82.15.4992
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发表时间：
1985-08
影响因子：
11.1
通讯作者：
M. Nemer;D. Wilkinson;E. C. Travaglini;E. Sternberg;T. Butt
中科院分区：
文献类型：
--
作者：
M. Nemer;D. Wilkinson;E. C. Travaglini;E. Sternberg;T. Butt
金属硫蛋白(Metals thioneins，MTS)是一个富含半胱氨酸并结合重金属的蛋白质家族。从海胆MT的mRNA序列中获得了其氨基酸序列，并与不同来源的MT序列进行了比较。一个由10个氨基酸组成的高度保守的序列，即“中央片段”，位于脉孢子虫、酵母和果蝇MT分子的中心附近，也是哺乳动物和海胆MT的推测结构域的中心。海胆的羧基末端半胱氨酸类似哺乳动物的9-半胱氨酸氨基末端MT结构域I，无论是在这个中心片段的存在还是在半胱氨酸残基的相对位置上都是如此。相反，海胆氨基末端半胱氨酸含有11个半胱氨酸，与哺乳动物的羧基末端MT结构域II相似，因为它唯一地富含邻近的半胱氨酸。这些海胆和哺乳动物MT半部分的颠倒顺序似乎只是基于包含中央片段的结构的精致的多样性的一个方面。这种多样性的另一个变异是中心片段的复制，这在果蝇和螃蟹MTS中很明显。
The metallothioneins (MTs) constitute a diverse family of proteins, which are enriched in cysteines and bind heavy metals. The amino acid sequence of sea urchin MT has been obtained from its mRNA sequence and compared with MT sequences of various sources. A largely conserved sequence of 10 amino acids, the "central segment," is located near the center of the MT molecules of Neurospora, yeast, and Drosophila and the center of putative domains in mammalian and sea urchin MTs. The sea urchin carboxyl-terminal-half MT resembles the mammalian 9-cysteine amino-terminal MT domain I, both in the presence of this central segment and in the relative placement of cysteine residues. Conversely, the sea urchin amino-terminal-half MT, containing 11 cysteines, resembles the mammalian carboxyl-terminal MT domain II in its exclusive enrichment in vicinal cysteines. The reversed order of these sea urchin and mammalian MT halves appears to be just one aspect of a diversity based on the elaboration of structures containing the central segment. Still another variation in this diversity is the duplication of the central segment, apparent in Drosophila and crab MTs.