Half‐life of tRNA Containing N⁶(Δ²‐isopentenyl)adenosine in Lactobacillus acidophilus ATCC 4963

Abstract

tRNA containing N'-(A^ isopentenyl)adenosine may be precursors for the plant hormone cytokinin. To discriminate between tRNA containing and not containing cytokinin nucleotides, double labelling experiments were made by the use of l2'*C]-mevalonic acid and ['H-methyl]-methionine. At a generation cycle of 2 h for Lactobacillus addophilus ATCC 4963, the half-lives of tRNA labelled with [^H-methylJ-methionine and l2-'^C]-mevalonic acid are similar, namely 3 h. Isopentenylation of tRNA could be measured to be maximally 1:10. Abbreviations: IPade

On the biogenesis of cytokinins in Lactobacillus acidophilus ATCC 4963

“…The tRNA was maximally radioactive at 3 h after the pulse period. In these experiments and in ear- lier ones (Leineweber andKlatnbt 1974, Helbach et al 1978) a half-life of 3 h of tRNA in Lactobacillus acidophilus was determined. There seetns no doubt, that cytokinins in Lactobacillus acidophilus are produced by tRNA hydrolysis.…”