Subunit fusion confers tolerance to peptide insertions in a virus coat protein
Subunit fusion confers tolerance to peptide insertions in a virus coat protein
复制标题
DOI：
10.1006/abbi.1997.0312
复制
发表时间：
1997-11-01
影响因子：
3.9
通讯作者：
Peabody, DS
中科院分区：
文献类型：
--
作者：
Peabody, DS
将称为Flag的八肽序列插入噬菌体MS 2外壳蛋白的两个不同位置，并测定其对蛋白质折叠和病毒组装的影响。重组体的翻译阻遏物和衣壳组装功能的测定表明，当将肽插入其N-末端时，外壳蛋白正确折叠成结合RNA的形式（即，二聚体），但对于衣壳装配是有缺陷的。另一方面，预期将Flag插入展示为表面环的重组蛋白不能正确折叠，因此被蛋白水解降解。外壳二聚体的两个亚基的遗传融合导致蛋白质对这些结构扰动的耐受性大大提高，并且主要纠正伴随Flag肽插入的缺陷。单链外壳蛋白对尿素变性的抗性增加表明融合二聚体比野生型稳定得多。寡聚体亚基的共价连接可能代表了工程化增加蛋白稳定性的一般策略。(C)1997年学术出版社。
An octapeptide sequence called Flag was inserted into the bacteriophage MS2 coat protein at two different locations and its effects on protein folding and virus assembly mere determined, Assays of the translational repressor and capsid assembly functions of the recombinants show that when the peptide is inserted at its N-terminus coat protein folds properly into the form that binds RNA (i.e., the dimer), but is defective for capsid assembly, On the other hand, a recombinant protein which is expected to display the Flag insertion as a surface loop does not fold correctly and, as a consequence, is proteolytically degraded. Genetic fusion of the two subunits of the coat dimer results in a protein considerably more tolerant of these structural perturbations and mostly corrects the defects accompanying Flag peptide insertion. Increased resistance of the single-chain coat protein to urea denaturation indicates that the fused dimer is substantially more stable than wild type, Covalent joining of subunits of oligomers probably represents a general strategy for engineering increased protein stability. (C) 1997 Academic Press.