母鸡输卵管溶菌酶信使核糖核酸5'末端的结构

Structure of the 5' terminus of hen oviduct lysozyme messenger ribonucleic acid.

作者信息

Eschenfeldt W H, Cohen B G, Rhoads R E

出版信息

J Biol Chem. 1983 Nov 10;258(21):13076-81.

Abstract

Lysozyme mRNA (mRNAlys) was purified from hen oviduct poly(A)-containing RNA by hybridization, labeled with NaB[3H]4 and digested with RNase T1. This revealed the presence of equal amounts of two major oligonucleotides having structures of m7Gppp(Np)7 and m7Gppp(Np)4 plus minor amounts of m7Gppp(Np)2 and m7GpppNp. The total mRNAlys contained the cap structures m7Gpppm6Am, m7GpppGm, m7GpppAm, m7GpppCm, m7GpppA, and m7GpppG, in decreasing order of abundance. The m7Gppp(Np)7 oligonucleotide contained only A-caps and the m7Gppp(Np)4, only G-caps. 32P-labeled 5'-terminal T1-oligonucleotides were prepared, and at least 12 different types were observed, the most abundant being m7Gppp(Np)7 and m7Gppp(Np)4. Their sequences were determined to be m7Gppp(m6)AmNmUCCCG and m7GpppGmNmAG. Taken together with the findings of Grez et al. (Grez, M., Land, H., Giesecke, K., Schutz, G., Jung, A., and Sippel, A. E. (1981) Cell 25, 743-752), these results indicate that in the genomic sequence AGCTTGCAGTCCCGT, 52% of the mRNAlys molecules begin at the underlined A residue and 38% at the underlined G residue.

摘要

溶菌酶信使核糖核酸（mRNAlys）通过杂交从含有多聚腺苷酸（poly(A)）的鸡输卵管核糖核酸中纯化出来，用NaB[3H]4进行标记，并用核糖核酸酶T1消化。这揭示了存在等量的两种主要寡核苷酸，其结构分别为m7Gppp(Np)7和m7Gppp(Np)4，还有少量的m7Gppp(Np)2和m7GpppNp。总的mRNAlys包含帽结构m7Gpppm6Am、m7GpppGm、m7GpppAm、m7GpppCm、m7GpppA和m7GpppG，丰度依次递减。m7Gppp(Np)7寡核苷酸只包含A帽，而m7Gppp(Np)4只包含G帽。制备了32P标记的5'-末端T1寡核苷酸，观察到至少12种不同类型，最丰富的是m7Gppp(Np)7和m7Gppp(Np)4。它们的序列被确定为m7Gppp(m6)AmNmUCCCG和m7GpppGmNmAG。结合格雷兹等人（Grez, M., Land, H., Giesecke, K., Schutz, G., Jung, A., and Sippel, A. E. (1981) Cell 25, 743 - 752）的研究结果，这些结果表明在基因组序列AGCTTGCAGTCCCGT中，52%的mRNAlys分子从下划线标注的A残基处开始，38%从下划线标注的G残基处开始。