Table 2 Adaptive strategies of psychrophilic prokaryotes to cope with low temperatures and potential adaptation in C. subellipsoidea C-169
Adaptive strategy | Prokaryotic genes or events involved in the process | C-169-specific genes potentially involved in the process |
|---|---|---|
Increased fluidity of cellular membranes at low temperature | Unsaturated fatty acid (FA) synthesis genes, FA desaturases | Lipid biosynthesis genes, including FA synthase type I, FA desaturases, lipases |
Reduction of freezing point of cytoplasm and stabilization of macromolecules | Genes for synthesis of compatible solutes, membrane transporters, antifreeze proteins and ice-binding proteins | Production of antifreeze lipoproteins, exopolysaccharides and glycoproteins: lipid biosynthesis genes, including FA synthase type I and FA ligases; carbohydrate metabolism genes, including glycosyl hydrolases and glycosyl transferases |
Protection against reactive oxygen species | Catalases, peroxidases, superoxide dismutases, oxidoreductases | Dioxygen-dependant FA desaturases, DOPA-dioxygenase, loss of the gene encoding photosystem 1 subunit PsaN |
Maintain catalytic efficiency at low temperatures | Global change in amino acid composition of encoded proteins to decrease protein structural rigidity | No apparent change in global amino acid composition relative to mesophilic plants and green algae |