Nucleotide sequence of theEuglena gracilischloroplast genes for isoleucine, phenylalanine and cysteine transfer RNAs and ribosomal protein S14

Euglena gracilischloroplast ribosomal protein operon: a new chloroplast gene for ribosomal protein L5 and description of a novel organelle intron category designated group III

“…This region is located 2.8 kbp distal to, and in the same polarity as, the previously described rp123-rpl2-rpsl9-rp122-rps3 Euglena chloroplast ribosomal protein gene cluster (18). Immediately downstream from the 5 genes described in this paper, and in the same polarity are the genes trnl-rpsl4-trnF-trnC (19). Exon-Intron Boundaries of rplJ6 and rps8 Determined by cDNA Sequence Analysis.…”

“…A plasmid library of chloroplast BglII restriction fragments of 3.0-5.0 kb in size cloned in the BamHI site of pBSwas constructed with E. coli XL-1 Blue as host. Replica filters of the library were screened by colony hybridization (23) with 32P-labeled DNA probes from purified EcoM fragment, and also from a 600 bp DNA fragment encoding the E. gracilis 3'-end of rpsl4 and the complete trnF and trnC genes (19). Plasmid pEZC942, which contains the 4.2 kb E. gracilis chloroplast BglIl fragment BgLJ2, (Fig.…”

“…We are interested in the organization, expression, RNA maturation pathways, and novel introns of Euglena chloroplast ribosomal protein genes, and the evolutionary relationship of these genes and introns to other comparable ribosomal protein operons (17,18,19,33). The region under study is located in the E. gracilis chloroplast EcoRI fragments EcoM and EcoA (24).…”

“…The 2.3, 2.5, and 2.9 kb mRNAs are even larger precursors of the ribosomal protein transcription unit, containing cistrons distal to rplS. The 4.5 to 8.3 kb transcripts are much larger than the region encoding the 5 ribosomal protein genes, and are presumed to be part of a larger precursor mRNA, perhaps encoding regions of the flanking ribosomal protein genes (19). The intron specific probes hybridize to unique, but rare and presumably unspliced, chloroplast RNAs (data not shown).…”

“…In the photosynthetic protist, Euglena gracilis, 11 chloroplast ribosomal protein genes have been characterized, including rps7-rpsl2 (16), rp120 (17), rp123-rp12-rpsl9-rp122-rps3 (18), rpsl4 (19), and rps4-rpsll (Stevenson, J. and Hallick, R.B., manuscript in preparation). In the present paper, we describe a novel chloroplast ribosomal protein operon that contains the five genes, rp116-rp114-rp15-rps8-rpL36.…”