Open AccessThe effect of a unique D-loop structure of a minor tRNAleuUUAfromStreptomyceson its structural stability and amino acid accepting activity
Author(s) -
Yoshitaka Ueda,
Izumi Koyanagi,
Kiyonori Miura
Publication year - 1992
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/20.15.3911
Subject(s) - biology , transfer rna , aminoacylation , mutant , leucine , streptomyces , biochemistry , amino acid , protein biosynthesis , ef tu , rna , streptomycetaceae , gene , actinomycetales , genetics , bacteria
Streptomyces bldA gene, which encodes a tRNA corresponding to a very minor leucine codon, UUA, regulates pleiotropic gene expression which is involved in sporulation and secondary metabolism. The unique structural feature of this tRNA is the lack of GG sequence in dihydrouridine loop (D-loop) that generally is conserved in tRNAs involved in cytoplasmic protein biosynthesis. In order to investigate the relationship between the D-loop structure and the stability and leucine accepting activity of this tRNA, the wild and D-loop mutant tRNA transcripts were constructed with T7 RNA polymerase in vitro. The wild type tRNA(UUALeu) showed the structural stability and leucine accepting activity at physiological temperature for Streptomyces. The E.coli type D-loop mutant, which has a larger loop size and contains a GG doublet, exhibited increased thermostability. The kinetical analyses of the aminoacylation reaction of tRNA(UUALeu) with S.lividans and E.coli leucyl-tRNA synthetase (LeuRS) suggest there is a unique recognition mechanism of Streptomyces LeuRS toward tRNA(UUALeu).