期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：10
页码：5724-5729
DOI：10.1073/pnas.0931462100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The RNase P protein gene (rnpA) completely overlaps the rpmH gene (encoding ribosomal protein L34) out of frame in the thermophilic bacterium Thermus thermophilus. This results in the synthesis of an extended RNase P protein (C5) of 163 aa and, by inference, of 240 aa in the related strain Thermus filiformis. Start codons of rnpA and rpmH, apparently governed by the same ribosome binding site, are separated by only 4 nt, which suggests a regulatory linkage between L34 and C5 translation and, accordingly, between ribosome and RNase P biosynthesis. Within the sequence encoding the N-terminal extensions and downstream of rpmH, several Thermus species exhibit in-frame deletions/insertions, suggesting relaxed constraints for sequence conservation in this region. Roughly the N-terminal third of T. thermophilus C5 was further shown to be dispensable for RNase P function in vitro by using a precursor tRNAGly substrate from the same organism. Taken together, these data reveal a mode of gene expression that is to our knowledge unprecedented in bacteria.
