Arginine
From FoldIt Wiki
Foldit's version of Arginine
Arginine (R) is a hydrophilic Amino acid. Its shape on Foldit is unique.
Because Arginine's Sidechain can be manipulated in so many different ways, it is often a good choice if you want to manually adjust a sidechain and then Wiggle to gain points. Adjusting an arginine can change things quite radically.
More information can be found at http://en.wikipedia.org/wiki/Arginine
