Vioque A
Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Isla de la Cartuja, Universidad de Sevilla-CSIC, Avenida Americo Vespucio s/n, 41092 Sevilla, Spain.
Nucleic Acids Res. 1997 Sep 1;25(17):3471-7. doi: 10.1093/nar/25.17.3471.
The RNase P RNA gene (rnpB) from 10 cyanobacteria has been characterized. These new RNAs, together with the previously available ones, provide a comprehensive data set of RNase P RNA from diverse cyanobacterial lineages. All heterocystous cyanobacteria, but none of the non-heterocystous strains analyzed, contain short tandemly repeated repetitive (STRR) sequences that increase the length of helix P12. Site-directed mutagenesis experiments indicate that the STRR sequences are not required for catalytic activity in vitro. STRR sequences seem to have recently and independently invaded the RNase P RNA genes in heterocyst-forming cyanobacteria because closely related strains contain unrelated STRR sequences. Most cyanobacteria RNase P RNAs lack the sequence GGU in the loop connecting helices P15 and P16 that has been established to interact with the 3'-end CCA in precursor tRNA substrates in other bacteria. This character is shared with plastid RNase P RNA. Helix P6 is longer than usual in most cyanobacteria as well as in plastid RNase P RNA.
已对10种蓝细菌的核糖核酸酶P RNA基因（rnpB）进行了表征。这些新的RNA与先前可得的RNA一起，提供了来自不同蓝细菌谱系的核糖核酸酶P RNA的全面数据集。所有异形胞蓝细菌，但所分析的非异形胞菌株均无，含有短串联重复序列（STRR），这些序列增加了螺旋P12的长度。定点诱变实验表明，STRR序列在体外催化活性中并非必需。STRR序列似乎最近并独立地侵入了形成异形胞的蓝细菌中的核糖核酸酶P RNA基因，因为密切相关的菌株含有不相关的STRR序列。大多数蓝细菌核糖核酸酶P RNA在连接螺旋P15和P16的环中缺乏已确定与其他细菌前体tRNA底物中的3'-末端CCA相互作用的GGU序列。这一特征与质体核糖核酸酶P RNA相同。在大多数蓝细菌以及质体核糖核酸酶P RNA中，螺旋P6比通常的更长。
