Disease relevance of rplJ

• The lethal effect of a plasmid resulting from transcriptional readthrough of rplJ from the rplKA operon in Escherichia coli [1].
• A single promoter, rplJp (P(L10)), has been identified in the rplJL operon from Streptomyces coelicolor A3(2) by promoter probe and primer extension analyses [2].

High impact information on rplJ

• These mutant plasmids exhibit normal transcription of rplJ-rplL but do not translate rplJ messenger RNA to yield plasmid-specified L10 ribosomal protein [3].
• Nucleotide sequence analysis demonstrates that all six mutants are single base pair alterations, occur within the leader region of the rplJ operon and are well removed from the presumed position of the primary promoter, PJ [3].
• We suggest that these mutations define a regulatory region within the leader sequence of the RNA transcript that serves to modulate the translational efficiency of rplJ messenger RNA [3].
• We have carried out measurements of the stable binding of the ribosomal protein (r-protein) complex L10-L7/L12 to mutant forms of the mRNA leader of the rplJ operon of Escherichia coli [4].
• One of the point mutations, base 1548, which lies within the L10-L7/L12-protected region, almost completely abolishes in vitro formation of a stable complex of L10-L7/L12 with rplJ mRNA leader, and a second point mutation, base 1634, strongly reduces it [4].

Biological context of rplJ

• Double transformation experiments with two compatible plasmids showed that the detrimental effect of the rplJ deletion on pGA217 can be reversed by the addition of a second plasmid which carries a functional gene for L7/L12 [1].
• We have also identified specific nucleotides in the rplJ mRNA leader that are protected by purified L10-L7/L12 from methylation by dimethyl sulfate in vitro [5].

Other interactions of rplJ

• Second, the four ribosomal protein genes are organized into two separate transcriptional units; rplK and A are in one unit and rplJ and L are in the second unit [6].
• We have constructed mutants in the untranslated leader region of a rplJ-lacZ fusion by oligonucleotide-directed mutagenesis [7].
• A high copy number plasmid that carries the promoter PJ, intact rplJ and a deletion of the 3' terminal portion of rplL is detrimental to the growth of the host bacterium [3].

References