Chloroplast rp123 loci potentially coding for a polypeptide homologous to the E. Coli L23 ribosomal protein are frame-shifted in spinach and several other plants, indicating that these loci are pseudogenes. In tobacco, tp123 constitutes a continuous open reading frame of 93 codons and its transcript initiates at least 66 bp upstream from the initiation codon. The N-terminal amino acid sequence of a 13 kDa protein from the 50 S subunit of tobacco chloroplast ribosomes matches that derived from the tobacco rp123 locus. This shows that rp123 is a functional gene in tobacco. © 1991.
Yokoi, F., Tanaka, M., Wakasugi, T., & Sugiura, M. (1991). The chloroplast gene for ribosomal protein CL23 is functional in tobacco. FEBS Letters, 281(1–2), 64–66. https://doi.org/10.1016/0014-5793(91)80359-B