5S rRNA binding proteins from the hyperthermophilic archaeon, Pyrococcus furiosus.

A determination was made of the nucleotide sequence of the 2719 bp region of a ribosomal protein gene cluster (PfeL32-PfeL19-PfL18-PfS5-PfL30) containing a 5S rRNA binding protein L18 homolog of hyperthermophilic archaea Pyrococcus furiosus. The organization of the archaeal ribosomal protein gene cluster is similar to that in the spc-operon of Escherichia coli (L6-L18-S5-L30-L15) but has two additional genes, namely those encoding PfeL32 and PfeL19, which were identified as extra proteins that are apparently not present in bacterial E. coli. Using an inducible expression system, P. furiosus mature PfL18 protein and a mutant PfL18 with the basic N-terminal amino acid region deleted were produced in large amounts in E. coli and Northwestern analysis showed the N-terminal region of PfL18, including the conserved arginine-rich region, to have a significant role in 5S rRNA-PfL18 interaction.