Cloning and Characterisation of the Hint Homologue of the Thermophile Thermus thermophilus

Abstract

Screening of a genomic library of the thermophile Thermus thermophilus revealed a novel thermophilic hint gene, homologues of which are highly conserved in genera from archaea to mammals. Hint belongs to the HIT protein super-family, which contains two broad groups, Fhit, associated with tumour suppression in eukaryotes and Hint with putatitive protein kinase C inhibitory activity. In T. thermophilus the 321bp gene has a GC content of 67% overall and 94.4% in the third nucleotide position, with unusually no thymine as a wobble base. The gene product, a small highly conserved 11996Da predicted soluble cytoplasmic protein, offers an ideal opportunity to investigate thermostabilising amino acid substitutions. Here we report on the characterisation of the novel hint sequence.

Key Words:

• Thermus thermophilus
• hint
• HIT family
• protein kinase C inhibitor (PKCI)
• thermostable