Fig. 3.

Phylogenetic analysis of selected nxrB-like sequences. Sequences from the ETSP OMZ metagenomes are indicated in bold. Open and closed circles represent bootstrap values ≥70% and ≥90%, respectively. The arrow indicates the position of the outgroup (selenate reductase sequences). The scale bar corresponds to 10% estimated sequence divergence. The tree was calculated with a rapid bootstrapping algorithm (100 bootstrap iterations). No conservation filter was used, resulting in 512 alignment positions