Structure of an Escherichia coli tRNA operon containing linked genes for arginine, histidine, leucine, and proline tRNAs

Abstract

A plasmid containing a gene for the most abundant Escherichia coli leucine isoacceptor tRNA,tRNALeU (anticodon CAG) was isolated from the Clarke-Carbon bank of cloned E. coli DNA. The clone contains a 12.3-kilobase DNA insert which was mapped by F' DNA hybridization analysis to the region 82 to 89 min on the chromosome. The cloned tDNALeU corresponds to the minor of two chromosomal regions containing different amounts of DNA complementary to tRNAcAeu&. Sequencing of the tDNA region revealed it to contain a multimeric transcription unit consisting of four different tRNA genes. The genes are in the arrangement 5'-leader-tRNAc73-57 base pairs-tRNAgusG-20 base pairs-tRNALAeuG-42 base pairs-tRNAUGG-3'. Coordinate expression of the component tRNAs in vivo and the absence of intercistronic promoters indicated that all four tDNAs reside in the same operon. The tDNA sequence is bounded by a promoter element showing good agreement with the procaryotic consensus sequence and a GC-rich stem-loop element that corresponds to a rho-independent terminator. The promoter region contains a GC-rich sequence that agrees with a suggested consensus stringency control element and two domains possessing dyad symmetry which flank the Pribnow box and include the putative stringency control region.

Coupling of Escherichia coli hns mRNA levels to DNA synthesis by autoregulation: implications for growth phase control

“…We probed the same RNA samples used for the Q173 experiment in Fig. 1 for expression of the tRNA locus hisR (Hsu et aL, 1984). As shown in Fig.…”

Structure and organization of the transfer ribonucleic acid genes of Escherichia coli K-12.

“…The metT and argT transcription units coordinate the synthesis of seven and four tRNAs, respectively. Both operons are defined at the sequence level by single promoter and rho-independent-like terminator elements that are functional and in good agreement with the canonical consensus sequences (37,67). No recognizable promoter or terminator sequences occur in the intercistronic regions for either gene cluster.…”

Leucine tRNA family of Escherichia coli: nucleotide sequence of the supP(Am) suppressor gene

“…Studies of tRNA:aminoacyl-tRNA synthetase interaction as well as codon recognition have stimulated a considerable amount of biochemical and genetic work on the analysis of the E. coli tRNALeU isoacceptor family (4,11,15,19,23,44).…”

“…The map position of three of these genes, leuT, leuU, and leuV, has been only approximately determined (26). Two of these genes, leuT and leuV, code for tRNACA`G, the most abundant (4,23,25,26) and most frequently used (17,24) tRNALeU species. An E. coli operon containing a tRNACA`G gene together with genes for tRNAcA&, tRNAiG, and tRNAUGG has recently been sequenced (23).…”

“…Two of these genes, leuT and leuV, code for tRNACA`G, the most abundant (4,23,25,26) and most frequently used (17,24) tRNALeU species. An E. coli operon containing a tRNACA`G gene together with genes for tRNAcA&, tRNAiG, and tRNAUGG has recently been sequenced (23). This operon, whose tRNA&AuG gene probably corresponds to leuT was mapped in the 82 to 89-min region.…”