Procedure for production of hybrid genes and proteins and its use in assessing significance of amino acid differences in homologous tryptophan synthetase alpha polypeptides.
Procedure for production of hybrid genes and proteins and its use in assessing significance of amino acid differences in homologous tryptophan synthetase alpha polypeptides.
复制标题
杂合基因和蛋白质的产生程序及其在评估同源色氨酸合成酶α多肽中氨基酸差异的显着性中的用途。
DOI：
10.1073/pnas.78.4.2169
复制
发表时间：
1981
影响因子：
11.1
通讯作者：
Yanofsky,C
中科院分区：
文献类型：
--
作者：
Schneider,WP;Nichols,BP;Yanofsky,C
杂合色氨酸合成酶α和β多肽是通过大肠杆菌和鼠伤寒沙门氏菌的trpB-trpA区域之间的遗传重组产生的，所述trpB-trpA区域包含在相容的多拷贝质粒上。基因内重组减少，但在recA细胞中仍然明显。遗传交换发生在trpA内的许多位点，但是每个重组基因产生功能性α多肽，尽管与亲本多肽中的一个或另一个存在许多氨基酸差异。五个杂合色氨酸合成酶α亚基检查类似的亲本多肽的催化功能，但不同的热稳定性。稳定性差异表明，由于氨基酸的变化发生在这些蛋白质的进化过程中，随后的变化仅限于那些将允许保留所需的蛋白质构象。
Hybrid tryptophan synthetase alpha and beta polypeptides were produced by genetic recombination between the trpB--trpA regions of Escherichia coli and Salmonella typhimurium contained on compatible, multicopy plasmids. Intragenic recombination was decreased but still evident in recA cells. Genetic exchange occurred at many sites within trpA, but every recombinant gene produced a functional alpha polypeptide despite many amino acid differences from one or the other of the parental polypeptides. The five hybrid tryptophan synthetase alpha subunits examined resembled the parental polypeptides in catalytic function but differed in thermostability. The stability differences suggest that, as amino acid changes occurred in these proteins during the course of evolution, subsequent changes were limited to those that would allow retention of a desired protein conformation.