PHIST phylogeny and domain map. The PHIST tree (tree topology determined by bootstrapped neighbour joining based upon pairwise distances between instances of the PHIST domain; branch lengths assigned with least squares error minimisation; branches with <50% bootstrap support in red, 50% to 75% in blue, >75% in black) demonstrates conservation of the domain across Plasmodia. Colours indicate subfamilies (as determined by recognition by subfamily HMMs) and species conservation. Domain diagrams indicate organisational differences between subfamilies. The PHIST domain is carboxy-terminal in the PHISTc subfamily, regardless of length. In the PHISTa and b subfamilies a domain position of 100 to 200 amino acids from the amino-terminal methionine appears to be a general rule. In all the DnaJ containing members of the PHISTb subfamily, the DnaJ domain is carboxy-terminal to the PHIST domain. Members of the PHISTa subfamiliy are the shortest members of the PHIST family and are, as a whole, the most divergent and appear in a number of instances to be truncated. Note that PHIST domain representation is based on the annotated PlasmoDB  sequence, which in some cases lacks the first exon (for example, PFB0905c).