Nakajima S, Brown D J, Ueda M, Nakajima K, Sugiura A, Pattnaik A K, Nayak D P
Virology. 1986 Oct 30;154(2):279-85. doi: 10.1016/0042-6822(86)90454-x.
Two temperature-sensitive mutants of WSN influenza virus, ts-61S and ts-134, possess defects in the hemagglutinin (HA) gene. These defects are characterized as a defective intracellular transport of the HA at the nonpermissive temperature and a marked thermolability. The nucleic acid sequences of the HA gene of these two viruses, as well as a series of revertant viruses, were determined. The deduced amino acid sequences demonstrate that the HA of ts-61S varied from the wild type protein by three amino acids while that of ts-134 differed by two residues. For both mutants, analysis of revertant viruses indicated that the phenotype of transport inhibition at the nonpermissive temperature and heat lability were associated with a single amino acid change in the globular portion of the molecule. In the case of ts-61S, the critical change in the HA was the replacement of a serine residue at position 110 with that of a proline. The mutational defect in the HA of ts-134 was due to the substitution of a tyrosine residue at position 159 with that of a histidine residue. Four of five revertants of ts-134 were suppressor revertants, of which some of the compensatory changes did not restore thermostability to the HA.
WSN流感病毒的两个温度敏感突变体ts-61S和ts-134在血凝素（HA）基因上存在缺陷。这些缺陷的特征是在非允许温度下HA的细胞内转运存在缺陷以及明显的热不稳定性。测定了这两种病毒以及一系列回复病毒的HA基因的核酸序列。推导的氨基酸序列表明，ts-61S的HA与野生型蛋白有三个氨基酸不同，而ts-134的HA有两个残基不同。对于这两个突变体，对回复病毒的分析表明，在非允许温度下的转运抑制表型和热不稳定与分子球状部分的单个氨基酸变化有关。就ts-61S而言，HA中的关键变化是第110位的丝氨酸残基被脯氨酸取代。ts-134的HA中的突变缺陷是由于第159位的酪氨酸残基被组氨酸残基取代。ts-134的五个回复体中有四个是抑制性回复体，其中一些补偿性变化并未使HA恢复热稳定性。
