Thermus thermophilus as biological model

Abstract

Thermus spp is one of the most wide spread genuses of thermophilic bacteria, with isolates found in natural as well as in man-made thermal environments. The high growth rates, cell yields of the cultures, and the constitutive expression of an impressively efficient natural competence apparatus, amongst other properties, make some strains of the genus excellent laboratory models to study the molecular basis of thermophilia. These properties, together with the fact that enzymes and protein complexes from extremophiles are easier to crystallize have led to the development of an ongoing structural biology program dedicated to T. thermophilus HB8, making this organism probably the best so far known from a protein structure point view. Furthermore, the availability of plasmids and up to four thermostable antibiotic selection markers allows its use in physiological studies as a model for ancient bacteria. Regarding biotechnological applications this genus continues to be a source of thermophilic enzymes of great biotechnological interest and, more recently, a tool for the over-expression of thermophilic enzymes or for the selection of thermostable mutants from mesophilic proteins by directed evolution. In this article, we review the properties of this organism as biological model and its biotechnological applications.

Development of a Continuous Bioconversion System Using a Thermophilic Whole-Cell Biocatalyst

“…T hermophilic enzymes are promising tools for biotransformation owing to their high operational stability, cosolvent compatibility, and low risk of contamination (1)(2)(3). The direct use of recombinant mesophiles (e.g., Escherichia coli) having heterologous thermophilic enzymes at high temperatures results in the denaturation of indigenous enzymes and the elimination of undesired side reactions; therefore, highly selective whole-cell catalysts comparable to purified enzymes can be readily prepared.…”

Characterization of the P IB -Type ATPases Present in Thermus thermophilus

“…hermus thermophilus is an aerobic facultative Gram-negative bacterium that grows rapidly in the temperature range from 60°C to 80°C and which yields sufficient biomass to be a practical source for thermally stable proteins to be characterized by biophysical and structural methods (13). In addition, T. thermophilus can be genetically manipulated and can be used as a host for expressing recombinant proteins (25,43).…”

An Extreme Thermophile,Thermus thermophilus, Is a Polyploid Bacterium

“…The genome of the HB27 strain consists of a chromosome (1.89 Mb) and a megaplasmid (0.23 Mb), while that of the HB8 strain includes a plasmid (9.3 kb) coupled with a chromosome (1.85 Mb) and a megaplasmid (0.26 Mb) (13; see also the NCBI website [above]). This organism has attracted attention as one of the model organisms for genetic manipulation, structural genomics, and systems biology (9,44). In the case of the HB8 strain, the Structural and Functional Whole-Cell Project for T. thermophilus HB8, which aims to understand the mechanisms of all the biological phenomena occurring in the HB8 cell by investigating the cellular components at the atomic level on the basis of their three-dimensional (3-D) structures, is in progress (44).…”