Wang Y, Zhang Z, Ramanan N
Microbial Collection and Screening Laboratory, Institute of Molecular and Cell Biology, National University of Singapore.
J Bacteriol. 1997 May;179(10):3270-6. doi: 10.1128/jb.179.10.3270-3276.1997.
Here we present the first description of the presence of two distinct types of 16S rRNA genes in the genome of a (eu)bacterium, Thermobispora bispora. We cloned and determined the nucleotide sequences of all four rRNA operons of T. bispora. Sequence comparisons revealed that the genome of T. bispora contains two distinct types of 16S rRNA genes, each type consisting of two identical or nearly identical copies, and three identical copies of the 23S RNA gene. The nucleotide sequences of the two types of 16S rRNA genes differ at 98 nucleotide positions (6.4% of total nucleotides) together with six regions of deletion-insertions. None of the base substitutions or insertion-deletions corresponds to any of the approximately 600 evolutionarily invariable or rarely variable nucleotides, indicating that both genes are functional. Both types of 16S rRNA genes are transcribed and processed as determined by Northern (RNA) hybridization and reverse transcriptase-mediated PCR.
在此，我们首次描述了在（真）细菌嗜热双孢菌（Thermobispora bispora）基因组中存在两种不同类型的16S rRNA基因。我们克隆并测定了嗜热双孢菌所有四个rRNA操纵子的核苷酸序列。序列比较显示，嗜热双孢菌的基因组包含两种不同类型的16S rRNA基因，每种类型由两个相同或几乎相同的拷贝组成，以及三个相同拷贝的23S RNA基因。两种类型的16S rRNA基因的核苷酸序列在98个核苷酸位置（占总核苷酸的6.4%）存在差异，同时还有六个缺失-插入区域。没有任何碱基替换或插入-缺失与大约600个进化上不变或很少变化的核苷酸中的任何一个相对应，这表明这两个基因都是有功能的。通过Northern（RNA）杂交和逆转录酶介导的PCR确定，两种类型的16S rRNA基因都被转录和加工。
