The genome of the bacterial anaerobic hyperthermophile Thermotoga maritima was sequenced in 1999, and whole-genome comparative analysis revealed that 24% of its DNA sequence is most similar to that of archaeal species, many of which occupy the same environmental niches. Subsequent studies demonstrated that other members of the Thermotogales have undergone extensive horizontal gene transfer with archaeal species, resulting in a broad genomic diversity across different members of this order. Genes encoding sugar ABC (ATP binding cassette) transporters appear to have participated disproportionately in horizontal gene transfer between these lineages. This sequencing project is expected to reveal the full extent of genetic transfer of archaeal genes into this lineage and the possible transfer of genes among the members of the Thermotogales.
Seven members of the Thermotogales will be sequenced, so that a comprehensive database will be available to address research questions in evolution, biogeography, and biotechnology. Specific areas of interest include how archaeal genes have modified their transcriptional controls to function in a bacterial host, how ligand specificity of sugar binding proteins evolves in coordination with the specificities of their genes’ transcriptional regulators, and the impact of repeated sequences on DNA mobilization during horizontal gene transfer. This comprehensive database from several hyperthermophiles will provide a resource to discover new thermostable enzymes and examine new protein structures.
CSP project participants: Kenneth M. Noll (proposer) and J. Peter Gogarten (Univ. of Connecticut), and Karen E. Nelson (TIGR).