A full-length cDNA clone, LeEF-1, has been isolated from tomato for the alpha subunit of elongation factor 1 (EF-1 alpha), a polypeptide which plays a central role in protein synthesis. The 448 amino acid protein encoded by this cDNA appears highly homologous to other EF-1 alpha s having a high degree of similarity (75-78%) to EF1 alpha previously described from both lower eukaryotes and animals. Southern analysis indicated that EF-1 alpha belongs to a small multigene family of 4-8 members in tomato. The pattern of expression of EF-1 alpha mRNA in various tomato tissues was analyzed by Northern analysis, in vitro translation and in situ hybridization. EF-1 alpha mRNA is an abundant species and higher levels of mRNA were found in developing tissues such as young leaves and green fruit compared to the mRNA levels observed in older tissues. The increased levels of EF-1 alpha mRNA therefore appear to correlate with higher levels of protein synthesis in developing tissues.

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Genomic clones containing three genes for the small subunit (SSU) of ribulose bisphosphate carboxylase were isolated from tobacco. Detailed analysis was performed on two of these clones to give a clearer picture of this multigene family in tobacco. This analysis demonstrated that one of the clones contained a pseudogene that was unusual in that it was transcriptionally active. This is the first transcriptionally active pseudogene that has been reported in plants. In addition, another clone was found to contain coding sequences which are 100% homologous to a previously-cloned tobacco SSU gene (Mazur, B.J. and Chiu, C-F. [1985] Nuc. Acids Res. 13, 2372-2386), indicating that gene duplication and/or gene conversion may have played a role in the evolution of the tobacco SSU family.