Garrick M D, Bricker J, Garrick L M
Genetics. 1974 Jan;76(1):99-108. doi: 10.1093/genetics/76.1.99.
The beta chain of rabbit (Oryctolagus caniculus) hemoglobin has previously been reported to contain a single residue of isoleucine at beta(112). We have detected other rabbits with either zero isoleucyl residues or half a residue per beta chain. This character is polymorphic and inherited as a simple mendelian autosomal codominant.-Normally the modal number of ribosomes per polyribosome is 4 to 6 in reticulocyte lysates; but incubation of rabbit reticulocytes prior to lysis with L-o-methylthreonine (OMT), an isostere of isoleucine, leads to a bimodal distribution in lysates with 2-3 and 8-12 ribosomes as modes. This alteration has been attributed to ribosomal traffic jams caused by starvation for ile-tRNA at mRNA codons corresponding to the locations of isoleucyl residues at positions alpha(10), alpha(17), alpha(55) and beta(112). We have confirmed this interpretation by incubating OMT with reticulocytes from rabbits with integral, half integral and nil values for isoleucyl residues per beta chain to show that formation of the larger clusters of polyribosomes requires that beta(112) = ile.
此前有报道称，兔（穴兔）血红蛋白的β链在β(112)处含有单个异亮氨酸残基。我们检测到其他兔子的β链要么不含异亮氨酰残基，要么每条β链含半个残基。这一特征具有多态性，且作为简单的孟德尔常染色体共显性性状遗传。正常情况下，网织红细胞裂解物中每个多核糖体的核糖体众数为4至6个；但在用异亮氨酸的等电子体L - o - 甲基苏氨酸（OMT）在裂解前孵育兔网织红细胞后，裂解物中会出现双峰分布，众数分别为2 - 3个和8 - 12个核糖体。这种改变被归因于在对应于α(10)、α(17)、α(55)和β(112)位置异亮氨酰残基的mRNA密码子处，由于异亮氨酸 - tRNA饥饿导致的核糖体交通堵塞。我们通过将OMT与每条β链异亮氨酰残基数量为整数、半整数和零值的兔子的网织红细胞一起孵育，证实了这一解释，结果表明形成较大的多核糖体簇需要β(112) = 异亮氨酸。
