Fig. 5

(a) Heatmap showing completeness (left panel) or presence/absence (right panel) of metabolic pathways annotated by DRAM across five strains. Only pathways that were present in at least one genome are included. (b) Genomic structure of nitrogen metabolism-related gene clusters uniquely present in the Antarctic strains but absent from closely related species. The gene cluster includes narK (nitrate/nitrite transporter), narG, narH, and narI (subunits of nitrate reductase/nitrite oxidoreductase), and narJ (nitrate reductase molybdenum cofactor assembly chaperone), with adjacent tnp (transposase) and int (integrase) elements suggesting possible mobility. Arrows represent individual genes, and gray blocks indicate conserved gene arrangements among the strains. (c) Gene clusters associated with methane or ammonia oxidation conserved across the Antarctic strains. This region includes amo/pmoB, amo/pmoA, and amo/pmoC (ammonia/methane monooxygenase subunits), SIP (siderophore-interacting protein), adhD (aldehyde dehydrogenase D), adh (alcohol dehydrogenase), and hp (hypothetical protein). As in (b), arrows represent genes, and gray shading denotes conserved synteny among the three strains.