Two-piece tmRNA in cyanobacteria and its structural analysis.
tmRNA acts to rescue stalled bacterial ribosomes while encoding a peptide tag added trans-translationally to the nascent peptide, targeting it for proteolysis. The permuted gene structure found in a group of cyanobacteria is shown to produce a two-piece mature tmRNA, as had been observed previously for the independently permuted gene of alpha-proteobacteria. The pieces have been mapped onto the gene sequence and aligned for the permuted cyanobacterial tmRNA sequences, including four novel sequences. Structural probing and base pair co-variations support a secondary structure model in which two pairings in the tRNA-like domain hold the two pieces together, and the coding piece bearing the tag reading frame additionally contains a single transient pseudoknot and three other stem-loops. This represents a dramatic reduction in pseudoknot number from the five present in one-piece cyanobacterial tmRNA.
Gaudin
Cyril
C
Laboratoire de Biochimie Pharmaceutique, Faculté de Pharmacie, Université de Rennes I, UPRES Jeune Equipe 2311, IFR 97, 2 avenue du Pr Léon Bernard, 35043 Rennes cedex, France.
Zhou
Xiong
X
Williams
Kelly P
KP
Felden
Brice
B
D001483:Base Sequence; D000458:Cyanobacteria / Q000235:genetics*; D005798:Genes, Bacterial; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D012322:RNA Precursors / Q000032:analysis; D012329:RNA, Bacterial / Q000737:chemistry* / Q000235:genetics; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA
D012322:RNA Precursors; D012329:RNA, Bacterial; C096222:tmRNA