Figure 4. C1 domain tree
A phylogenetic tree for the C1 domain—with no genus-level filter and
inclusion of more distant hits (See Methods)—indicates a limited
taxonomic distribution of the domain. The largest group of sequences in
Chloroflexi places sister to domains found in Nitrospirae, Nitrospinae,
and Deltaproteobacteria. Within this clade, the branch along which C1 is
inferred to have fused into nitrite reductase genes in Chloroflexi is
labeled. C1 homologs that co-occur in ORFs with nitrite reductase are
indicated with magenta diamonds (NirS) or yellow diamonds (NirK).
Support values for selected bipartitions are labeled (aLRT/bb). Support
for other nodes is indicated with the following color scheme: Strong
support with both values ≥ 90 (black); weak support with both values ≤
50 (white); intermediate support with one or both values between 50 and
90 (grey); conflicting support, with one value ≤ 50 and the other ≥ 90
(grey).