Figure 3.

Core gene-based phylogeny (a) and inventory of select metabolic features of the thaumarchaeal variable proteome (b and c). (a) A maximum-likelihood tree of 301 concatenated genes, (b) depicts the presence (shown as white dots) or absence of genes in sequenced thaumarchaeal genomes, whereas (c) emphasizes the gene-neighborhood differences around the ectABCD operon involved in ectoine biosynthesis between Nitrosopumilus species. Asterisk (*), low-affinity phosphate transporters; ectA, L-2,4-diaminobutyrate Nγ-acetyltransferase; ectB, L-2,4-diaminobutyrate acetyltransferase; ectC, ectoine synthase; ectD, ectoine hydroxylase.