Is there any information about which parts of the catalyst may or may not need to be exposed for it to function properly? I don't know if the term active site applies, but basically I'm wondering what the equivalent is here.
Keeping the catalyst mostly buried would be great if you can manage it, but there is a spot that should have access to polar stuff: the nitrogens near the central metal. (Or the metal itself, but that's tough to get to, which is what the nitrogens are for: shuttling protons to the metal.) "Polar stuff" can be solvent, or it can be any buried polar group.
More info on the catalyst can be found here:
http://www.pnl.gov/news/release.aspx?id=883
and in the recent blog post & podcasts.
Oh, but for this puzzle, don't worry about anything besides building cool-looking, low-energy designs. :) Once we figure out the best way to give players bonuses for putting polar hydrogens near the nitrogen atoms of the catalyst, we'll give you more details about what we're looking for, and how to get the best score bonus.
I asked a similar question.
This puzzle had an issue where mutating the 2nd segment to GLY would crash Foldit. There is a new version up (http://fold.it/portal/node/994490).
Please play in that version. If you manually save your solution you can load it in the new puzzle.
Our two overarching goals for these hybrid catalyst/peptides: 1. put proton-donating groups like Asparagine and Histidine near the nitrogen atoms of the catalyst (to be emphasized in a follow-up puzzle), and 2. form a stable structure so strong that it freezes the catalyst in this conformation. (The catalyst is actually more flexible that it appears here - but this is the conformation it needs to adopt in order to produce hydrogen, which is why we're keeping it frozen for this design puzzle.) More details in the upcoming blog post.