FIG 5.

Maximum-likelihood phylogeny of 21 HMT PQQ-dependent dehydrogenase families identified in the nonredundant set of HMT proteins (blue) together with reference sequences in the NCBI NR database. Colors symbols indicate the presence of transmembrane domains, signal peptides, and binding motifs in the HMT enzymes. Enzymes that were among the top 40 most highly expressed genes in the DeepDOM metatranscriptomes are denoted with a purple triangle. Black circles denote nodes with >80% bootstrap support (see Materials and Methods for details).