Ribosomal protein gene cluster of Halobacterium halobium: nucleotide sequence of the genes coding for S3 and L29 equivalent ribosomal proteins

A 1643 base pair fragment encoding the S3 and L29 equivalent ribosomal proteins has been sequenced from the archaebacterium Halobacterium halobium. The incomplete open reading frame present upstream from the S3 gene encodes a protein homologous to the eubacterial ribosomal protein L22. The initiation codons of the S3 and L29 genes overlap with the termination codons of the upstream genes. A tight physical organization suggests that these genes are transcribed as a polycistronic operon. Peculiarities of the protein structure and gene organization are discussed.