Phylogenetic homology

In mammalians these metallothioneins normally possess chain lengths of 61 amino acids, of which 20 are invariant cysteines residues [58,316], These 20 residues participate in the binding of the up to twelve metal ions. Class II metallothioneins show little or no phylogenetic homology to the metallothioneins of class I, for instance, in sea urchins [317] and yeast [318]. Class III metallothio-... 

Sequence homologies are low within type 2 copper proteins. While similarities exist in protein folding or in the structure of the copper centers, they are not based on phylogenetic homologies in amino acid sequence. These similarities are solely the result of separate proteins evolving and adapting to similar functions. In contrast to type 1 copper centers, type 2 copper proteins developed primarily by convergent evolution. 

Rieppel (1980) Topographical homology Phylogenetic homology Homoplasy... 

Hydrozoa, such as A. victoria, and Anthozoa both belong to the phylum Cnidaria. In addition, fluorescent proteins have been isolated from planktonic Copepods, which belong to the evolutionary distant phylum Arthropodia [14], This wide phylogenetic distribution of GFP-like proteins might implicate that these proteins developed early in evolution and hence that almost every animal taxon can potentially contain GFP homologs [1],... 

Now described as a trp superfamily, more than 20 vertebrate trp homologs have been identified and these can be divided phylogenetically into three subfamilies trpC (termed canonical as they are most closely related to Drosophila trp), trpV and trpM. Some of these proteins are potential contenders for the capacitative calcium ion entry channel. In particular, expression of members of the TRPC and TRPV families in mammalian cells has been shown to augment capacitative calcium ion entry, but their role is still a matter for debate [17]. 

Blair, A., Ngo, L., Park, J., Paulsen, I. T. and Saier, M. H. Jr (1996). Phylogenetic analyses of the homologous transmembrane channel-forming proteins of the FoFi-ATPases of bacteria, chloroplasts and mitochondria, Microbiology, 142, 17-32. 

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