Phylogenetic tree of the H-cluster of FeFe-hydrogenases and NARs or NARs-like proteins

<p><b>Copyright information:</b></p><p>Taken from "The [FeFe] hydrogenase of has a chimeric origin"</p><p>http://www.biomedcentral.com/1471-2148/7/230</p><p>BMC Evolutionary Biology 2007;7():230-230.</p><p>Published online 16 Nov 2007</p><p>PMCID:PMC2216082.</p><p></p> Accession numbers of sequences are indicated when more than one sequence from a species is included. The numbers at the nodes represent the posterior probability resulting from a Bayesian inference. : H-clusters recovered from a metagenomic approach using DNA from total ciliate population in the rumen of a cow. The H1 block marks the "classical " [FeFe] hydrogenases and NAR's. Block 1 is characterized by the clade of (long and short – type) hydrogenases. It hosts also the majority of the rumen sequences plus the hydrogenases from the type-strain rumen ciliates , and . Block 2 marks the long-type hydrogenases from the anaerobic chytridiomycetes and and the (short) plastidic hydrogenases from the algae and . Block 3 marks H-clusters from rumen ciliates that are likely to lack hydrogenosomes. Block H2 marks a well supported clade of Fe hydrogenases dominated by . Besides and its close relatives, this clade consists of hydrogenases from the amoeboflagellate , the rumen ciliate , the free-living ciliate . and the rumen (meta) sequences . A fusion of the H-cluster with the 24 and 51 kDa modules has so far only been observed for the clade. The hydrogenase has no fused 24/51 kDa modules