Hi
I've only just started using this programme and it's really great! However, as a recently retired inorganic biochemist I would love to see selenomethionine and selenocysteine as options. Also, do you have the possibility of handling metalloproteins? I may be biased, but there are many major zinc and iron binding proteins out there!
In theory, yes, we could support additional amino acids in Foldit.
However, Foldit does not do any atomic orbital calculations (our modeling engine uses simple ball-and-stick molecular mechanics). I think the only difference between SeMET and MET would be a slightly larger atomic radius at the Se position (?), which is unlikely to have a serious effect on Foldit protein models.
We can also model metalloproteins, insofar as we can include a metal ion with the appropriate charge and atomic radius. But, without orbital calculations, we typically have to define the metal coordination geometry by hand.