NB: This tree has been constructed from a clustalW treefile that was produced by a server under the default settings. This means that distances have not been corrected for multiple substitutions and that indels have been included in the calculations of distances (however, in this specific case the indels were removed from the sequence files before submission). So the branch lenghts are nor proportional to evolutionary distance.
Bacterial MDHs cluster together, except for the Bacillus subtilis MDH, which behaves in an anomalous way. This could be explained by the fact that B. subtilis MDH is some 80% diffrerent from all other MDHs. (The horizontal bar represents 10% difference in amino acids).
The microbody sequences are indicated in magenta, mitochondrial sequences in green. It is obvious that the glycosomal, glyoxysomal and peroxysomal sequences arose several times in parallel from the transfer of a mitochondrial MDH to the microbodies. The phytomonas glycosomal MDH is related to T. brucei glycosomal MDH, despite its different substrate specificity. Morover the Trypanosomatid g- and mMDHs clearly are two distinct isoenzymes.