Pavlakis G N, Lockard R E, Vamvakopoulos N, Rieser L, RajBhandary U L, Vournakis J N
Cell. 1980 Jan;19(1):91-102. doi: 10.1016/0092-8674(80)90391-8.
The nucleotide sequence from the 5' terminus inward of one third of mouse alpha- and beta maj-globin messenger RNAs has been established. In addition, using 5' 32P end-labeled mRNAs as substrates and S1 and T1 nucleases as probes for single-stranded regions, the secondary structures of mouse and rabbit alpha- and beta-globin mRNAs have been analyzed. Our results indicate that the AUG initiator codon in both mouse and rabbit beta-globin mRNA is quite susceptible to cleavage with S1 and T1 nucleases, suggesting that it resides in a single-stranded exposed region. In contrast, the initiator AUG in the alpha-globin mRNA of both species is inaccessible to cleavage, indicating that it is either buried by tertiary structure or is base-paired. Since the rate of initiation of protein synthesis with beta-globin mRNA in rabbit reticulocyte is 30--40% faster than for alpha-globin mRNA, these results imply a possible correlation between the differential rates of initiation with these two mRNAs and the accessibility of the respective AUG initiator codons.
已确定小鼠α-和β-珠蛋白主要信使核糖核酸（mRNA）从5'末端向内三分之一的核苷酸序列。此外，以5' 32P末端标记的mRNA为底物，用S1和T1核酸酶作为单链区域的探针，对小鼠和兔的α-和β-珠蛋白mRNA的二级结构进行了分析。我们的结果表明，小鼠和兔β-珠蛋白mRNA中的AUG起始密码子很容易被S1和T1核酸酶切割，这表明它位于单链暴露区域。相反，这两个物种的α-珠蛋白mRNA中的起始AUG无法被切割，这表明它要么被三级结构掩盖，要么是碱基配对的。由于兔网织红细胞中β-珠蛋白mRNA的蛋白质合成起始速率比α-珠蛋白mRNA快30%-40%，这些结果意味着这两种mRNA起始速率的差异与各自AUG起始密码子的可及性之间可能存在关联。
