Figure 1

Consensus phylogeny of DsrAB sequences. Trees for reconstruction of the consensus tree (extended majority rule) were calculated using an alignment of 911 representative DsrAB sequences (clustered at 97% amino-acid identity) and an indel filter covering 530 amino-acid positions between the target sites of the most commonly used DSR1F and DSR4R primer variants. Remaining core sequences (n=378) of the clusters were subsequently added to the consensus tree without changing its topology. Scale bar indicates 10% sequence divergence. Bootstrap support (100 resamplings) is shown by split circles (top: maximum parsimony; bottom left: maximum likelihood; bottom right: neighbor joining) at the respective branches, with black, gray and white/absence indicating ⩾90%, 70%–90% and <70% support, respectively. DsrAB-carrying phyla are labeled in different background colors; gray background represents lineages with no closely related cultured representatives. Black arrows indicate the possible locations for the root of the tree according to paralogous rooting analysis. LA-dsrAB, laterally acquired dsrAB. Moorella thermoacetica dsrAB copy 1 clustered with the LA-dsrAB Firmicutes group.