In vitro processing of cucumber chloroplast tRNA(Leu)(CAA) precursor in a pea chloroplast soluble extract.
To study the sequential steps in the processing pathway of the chloroplast monocistronic intronless tRNA precursors, we examined cucumber chloroplast tRNA(Leu)(CAA) processing in a cucumber or pea chloroplast soluble extract. The tRNA(Leu)(CAA) precursor synthesized from SP6 RNA polymerase-directed transcription system, was used as a substrate. Incubation of the tRNA precursor with the pea extract resulted in processing of tRNA(Leu)(CAA) via 5'- and 3'-endonucleolytic cleavages followed by final trimming of extra 3' nucleotides by 3' exonuclease(s). No preferred order for endonucleolytic cleavages has been observed during the in vitro tRNA(Leu) processing and the simultaneous occurrence of the intermediates consisting of leader + tRNA(Leu) and tRNA(Leu) + trailer, indicate that either 5'- or 3'-endonucleolytic cleavage can occur as the first step in vitro.
Hande
S
S
Department of Biochemistry, Indian Institute of Science, Bangalore, India.
Jayabaskaran
C
C
D002457:Cell Extracts; D002736:Chloroplasts / Q000378:metabolism*; D018553:Cucumis sativus / Q000235:genetics*; D004722:Endoribonucleases / Q000378:metabolism; D005095:Exoribonucleases / Q000378:metabolism; D018532:Pisum sativum / Q000201:enzymology* / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional / Q000502:physiology*; D012356:RNA, Transfer, Leu / Q000378:metabolism*
D002457:Cell Extracts; D012322:RNA Precursors; D012356:RNA, Transfer, Leu; D004722:Endoribonucleases; D005095:Exoribonucleases