Eubacterial tmRNA sequences and uses thereof

#The present invention is directed to eubacterial tmDNA sequences and the corresponding tmRNA sequences. The present invention is further directed to alignments of eubacterial tmDNA sequences and use of the sequences and sequence alignments for the development of antibacterial drugs. The present invention is also directed to the use of the sequences for the development of diagnostic assays.

#The publications and other materials used herein to illuminate the background of the invention or provide additional details respecting the practice are incorporated by reference, and for convenience are respectively grouped in the appended List of References.

#Eubacterial tmRNAs (10Sa RNAs) are unique since they function, at least in E. coli, both as tRNA and as mRNA (for a review, see Muto et al., 1998). These ˜360±10% nucleotide RNAs are charged with alanine at their 3′-ends (Komine et al., 1994; Ushida et al., 1994) and also have a short reading frame coding for 9 to 27 amino acids depending on the bacterial species. E. coli tmRNA mediates recycling of ribosomes stalled at the end of terminatorless mRNAs; via a trans-translation process (Tu et al., 1995; Keiler et al., 1996; Himeno et al., 1997). In E. coli, this amino acid tag is co-translationally added to polypeptides synthesized from mRNAs lacking a termination codon, and the added 11 amino acid C-terminal tag makes the protein a target for specific proteolysis (Keiler et al., 1996).

#FIGS. 1A–1B show the effect of the annealing temperature (FIG. 1A) and magnesium concentration (FIG. 1B) on amplifying eubacterial tmRNA genes from genomic DNAs using PCR. A: Varying the annealing temperature from 50° to 70° C. during the PCR amplification of Thermus aquaticus (1). B; Varying the magnesium concentration to amplify tmDNA genes from Thermus aquaticus (1), negative effect of increasing the magnesium concentration), Acholeplasma laidlawii (2), positive effect of increasing the magnesium concentration, the upper band is the tmDNA gene) and from Mycoplasma salivarium (3), no discernible effect of magnesium ions in that concentration range). The arrows point toward the 4 novel tmDNA genes that have been sequenced.

#FIG. 2 shows the distribution of tmDNA sequences within eubacterial genomes. The circled phyla or subgroups contain tmDNA sequences and those shaded are new members of this category. The numbers shown close to each phylum are the 51 tmDNA sequences that have are disclosed herein and the numbers in parenthesis are the 53 tmDNA sequences that were previously known (summarized in Williams, 1999; Wower and Zwieb, 1999). The environmental samples are indicated with a dashed line as their connection to the tree is unknown. The 5 alpha-Proteobacteria in which tmDNA sequences were not detected by PCR analysis are labeled “PCR” and the 3 analyzed by Blast search of the complete, or nearly complete, sequenced genomes are labeled “database”.

#FIGS. 3A, 3B and 3C show the sequence alignment, structural domains and structural features for the tmRNA of several species of Firmicutes. The tmRNA sequences are set forth in SEQ ID NOs:67–87.

#The present invention is directed to eubacterial tmDNA sequences and the corresponding tmRNA sequences. The present invention is further directed to alignments of eubacterial tmDNA sequences and use of the sequences and sequence alignments for the development of antibacterial drugs.

#The novel eubacterial tmDNA sequences determined in accordance with the present invention are set forth in Tables 1–58, below. The alignment of tmRNA sequences is shown in FIGS. 3A–11B, which also show the structural domains and structural features of the tmRNA. The present invention also includes the tmRNA sequences set forth in these figures to the extent they differ from the sequences set forth in Tables 1–58.

#The sequences, especially as identified by the sequence alignment, represent targets for the development of drugs which may be broadly applicable to many kinds of bacteria, or may be broadly applicable only to a particular genera of phylum of bacteria, or may be specifically applicable to a single species of bacteria. Thus, the present invention is further directed to the development of drugs for the therapeutic treatment of bacteria, generically or specifically. Suitable drugs are developed on the basis of the tmRNA sequences as described herein.