FIGURE 2.

Phylogenetic relationship of “uptake” [NiFe]-hydrogenase large subunit structural genes. The phylogenetic tree was calculated for nucleotide sequences of the large subunit [NiFe]-hydrogenase genes of (primarily vent-derived) phylogenetically diverse Bacteria and Archaea. The scale bar denotes the number of substitutions per nucleotide position and bootstrap values are only indicated if greater than 80%. ClustalW alignments were performed prior to tree calculation using BioEdit (Hall, 1999) with the standard settings. The tree was calculated using seaview (Gouy et al., 2010) with maximum likelihood analysis (four rate classes) and bootstrap values were calculated with 100 replicates. The classification of the [NiFe]-hydrogenase genes was determined using the HydDB web tool (Sondergaard et al., 2016).