Abstract
A genomic DNA Iibrary was constructed from lO-day-old rice seedlings. We have isolated and sequenced two nuclear genes, rpl13 and rpl24 that encode chloroplast ribosomal proteins (r-proteins) L13 and L24 respectively. The genomic clone of rpl13 spans 3.0kb and contains three introns. The genomic clone of rpl24 spans 3.3kb and also contains three introns. All intron/exon junctions follow the GT/AG rule. In rpl24, the second intron exists between the DNA sequence encoding the chloroplast targeting signal and the mature protein. In rpl13, there is no intron between them but the first intron exists in the NTE (N-terminal extension) which is an extended amino acid sequence from the eubacterial r-protein homologue. The sequences of the 5'-flanking regions of both genes lack a canonical TATA box. However, several putative transcription regulatory motifs reported in spinach and Arabidopsis were also observed in this region of both genes, indicating that nuclear encoded chloroplast r-protein genes of rice have the same transcriptional regulatory system as dicots.
