RNA-Binding Properties of an Unusual Ribosomal Protein TL5 from Thermus thermophilus

V. A. Meshcheryakov,¹ O. I. Gryaznova,¹ N. L. Davydova,¹ E. S. Mudrik,¹ A. A. Perederina,¹ K. S. Vasilenko,¹ G. M. Gongadze,^1,2 and M. B. Garber¹

¹Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142292 Russia; fax: (7-095) 924-04-93; E-mail: gongadze@vax.ipr.serpukhov.su

²To whom correspondence should be addressed.

Submitted November 28, 1996; revision submitted December 28, 1996.

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The gene encoding the 5S rRNA-binding ribosomal protein TL5 from Thermus thermophilus, an extremely thermophilic species, was expressed in E. coli. A method for isolation of TL5 from the overproducing strain was developed. Samples of TL5 protein isolated from ribosomes and the overproducing strain displayed identical RNA-binding properties. Circular dichroic spectroscopy was used to calculate the secondary structure of the protein. TL5 was shown to form a stable complex with the 3´-terminal fragment of 5S rRNA, which is similar to the fragment of E. coli RNA that binds to L25 protein. The data suggest that TL5 from T. thermophilus and L25 from E. coli bind to similar sites on the 5S rRNA molecule.

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KEY WORDS: overexpression of ribosomal protein TL5, 5S rRNA--protein complex, Thermus thermophilus.

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