Physiology and regulation of the lysine/arginine biosynthesis of the hyperthermoacidophilic crenarchaeon Sulfolobus solfataricus. (FWOAL482)

Lysine is synthesized via two well characterized pathways: (i) the diaminopimelate pathwy that is used by most bacteria and plants, (ii) the alpha-aminoadipate pathway (AAA) that is found in yeast and fungi. The thermophilic bacterium Thermus thermophilus synthesizes lysine through a modified AAA pathway in which the conversion of AAA to lysine proceeds in five steps that are equivalent to the conversion of glutamate to ornithine in the arginine pathway. Such a modified pathway might on basis of in silico studies also be operational in the crenarchaeon Sulfolobs solfataricus, where these enzymes might fulfil a double role, in contrast to Thermus where the two pathways for biosynthesis of arginine and of lysine exist side by side. To unravel the mechanism of arginine and lysine biosynthesis in S. solfataricus, knock-out mutants of S. solfataricus will be constructed, biosynthettic genes will be amplified, overexpresed in E. coli and the recombinant enzymes chracterized. Furthermore, LysM-mediated regulation of gene transcription will be analyzed.

Keywords:arginine, thermophiles, Lrp, lysine, archaea, transcription regulation, Sulfolobus

Disciplines:Biological sciences