STRUCTURE AND TRANSCRIPTION OF THE L11-L1-L10-L12 RIBOSOMAL-PROTEIN GENE OPERON FROM THE EXTREME THERMOPHILIC ARCHAEON SULFOLOBUS-ACIDOCALDARIUS

We have cloned and sequenced four ribosomal protein genes from the ext reme thermophilic archaeon Sulfolobus acidocaldarius P1. These genes c ode for proteins equivalent to L11, L1, L10 and L12 from Escherichia c oli. The genes for the Sulfolobus L11, L1, L10 and L12 proteins are ar ranged in the same order as the equivalent genes in E. coli, i.e. L11- L1-L10-L12, and are transcribed as a single unit. Sequences resembling the consensus sequence for archaeal promoters have been detected upst ream of the transcription initiation site. Transcription ends at sever al sites following a pyrimidine-rich region. The genes for proteins L1 1, L10 and L1 start with unusual initiation codons: GUG in the case of the L1 and L10 genes; and UUG in the case of L11. There are overlappi ng stop/start codons between the L11 and L1 genes, and between the L1 and L10, suggesting that the translation of the four genes might be co upled as in the bacteria.