Conclusion ERp18
It has been suggested that the ERp18 protein is unique to multi-celluar organisms and in that group is quite highly conserved. What also may be concluded is that the ERp18 is part of a unique family of proteins which belongs to a larger 'super family' of thioredoxin proteins and contains the specific active site motif CGAC motif. Further analysis is needed to dertermine proteins containing the CXXC active motif have a common ancestor, or if the motif has evolved convergently in several classes of protein
Structural analysis supported ERp18's classification as a thioredoxin protein. 3D modelling identified a catalytic site pertaining to an area of high evolutionary conservation. This catalytic site contained a CXXC residue motif - ubiquitous of all thioredoxin proteins. Furthermore, binding pockets were identified at the catalytic site by several bioinformatics programs. A DALI search identified numerous thioredoxin and thioredoxin-like proteins as being structurally similar, supporting the classification of ERp18 as a thioredoxin. Furthermore, information about the conformation and folding of ERp18 identified a thioredoxin fold. Recent literature has identified ERp18 as a dimer with a single protein molecular weight of 16.4 kDa, leading to the renaming of ERp18 as ERp16.
Future research into ERp18 (now ERp16) should confirm whether the protein fits in its predicted class, or whether it may be a novel representative of a new thioredoxin class. SOMETHING LIKE THIS TO CONCLUDE?
