The amino acid sequence of tryptophanyl tRNA Synthetase from Bacillus stearothermophilus
The amino acid sequence of tryptophanyl tRNA Synthetase from Bacillus stearothermophilus
复制标题
嗜热脂肪芽孢杆菌色氨酸tRNA合成酶的氨基酸序列
DOI：
10.1016/0014-5793(77)80471-7
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发表时间：
1977
期刊：
影响因子：
3.5
通讯作者：
B. Hartley
中科院分区：
文献类型：
--
作者：
G. Winter;B. Hartley
不同氨基酸特异性的氨酰tRNA合成酶具有不同的四级结构，范围从2 X 37 000道尔顿的二聚体到1 X 110 000道尔顿的单体[1]。初步看来，这些酶似乎不太可能具有丝氨酸蛋白酶所示的序列同源性[2]。然而，肽图谱、以大于摩尔产率分离几种胰蛋白酶肽以及更详细的序列研究已经揭示，具有大多肽链的酶（异亮氨酰-、亮氨酰-、甲硫氨酰-和缬氨酰-tRNA合成酶）含有广泛的序列内部重复[3-61]。因此，较大的链可能是由最初编码约40000道尔顿的链的共同祖先基因的复制和融合产生的。比较这些酶的一级和三级结构可以解决这个问题。完整的氨基酸序列显然是这种比较所需要的，作为第一个贡献，我们提供了嗜热脂肪芽孢杆菌（Bacillus stearothemophilus）的N-乙酰基tRNA合成酶的序列，这是一个2 × 37000道尔顿的二聚体。
Amino acyl tRNA synthetases of different amino acid specificities have diverse quaternary structures, ranging from dimers of 2 X 37 000 daltons to monomers of 1 X 110 000 daltons [l]. Prima facie, it seems unlikely that these enzymes will have the kind of sequence homology shown by the serine proteases [2]. Peptide mapping, isolation of several tryptic peptides in greater than molar yield, and more detailed sequence studies have revealed, however, that the enzymes with large polypeptide chains (isoleucyl-, leucyl-, methionyl-and valyl-tRNA synthetases) contain extensive internal repetition of sequence [3-61. The larger chains could therefore have arisen by duplication and fusion of common ancestral genes originally coding for chains around 40 000 daltons. Comparisons of the primary and tertiary [7-81 structures of several of these enzymes may resolve this question. Complete amino acid sequences are obviously desirable for such comparisons, and as the first contribution we offer the sequence of tryptophanyl tRNA synthetase from Bacillus stearothemophilus, a dimer of 2 X 37 000 daltons.