10.1371/journal.pbio.1000146.g002 George Hausmann George Hausmann Christian von Mering Christian von Mering Konrad Basler Konrad Basler Ptc and Disp, two key proteins the Hh pathway, in their evolutionary context. Public Library of Science 2009 proteins hh evolutionary 2009-06-30 00:55:06 Figure https://plos.figshare.com/articles/figure/_Ptc_and_Disp_two_key_proteins_the_Hh_pathway_in_their_evolutionary_context_/563306 <p>(A) A phylogenetic tree of proteins related to Patched, limited to proteins that are full-length (i.e., those that contain all 12 transmembrane segments), is shown. The tree is color-coded according to the taxonomy of the organisms in which the respective proteins are found. Note one particular family of deeply branching bacterial Ptc homologs, the HpnN family, which encodes a transporter that is predicted to be associated with hopanoid biosynthesis. (B) A typical hopanoid is shown, next to cholesterol, a typical sterol. (C) Sequence alignment of selected HpnN family members with the most common reciprocal-best-match, the Disp family, is shown. Only six sequences are shown (three bacterial and three eukaryotic proteins); the alignment is restricted to transmembrane segments 2 to 6, which form the so-called SSD. (D) and (E) Evidence is shown for a functional association between HpnN-family transporters and HpnF; the latter being the enzyme that catalyzes the first step of hopanoid biosynthesis. Both genes tend to be either present or absent together in a given genome in proteobacteria and occasionally occur in direct chromosomal proximity.</p>