Discovering critical residues in glutathione reductase - Gentoo

Figure 8: Phe254, a surface hydrophobic residue. See text for discussion.
Moving away from residues involved in the active site, one can examine
where hydrophobic conserved residues fall within the protein. As Kendrew's
rules say, (1) Hydrophilic residues are on the surface, (2) Hydrophobic residues
are in the core, and (3) Any violation of the above rules indicates function.
Following this, there is an odd occurrence of a 100% conserved hydrophobic
residue on the surface of the protein away from the active site, Phe354 (Figure
8). As this is grossly energetically unfavorable, it must serve some purpose,
although what purpose exactly remains unclear. If one looks at nearby nonhydrophobic
conserved residues, one finds Ala39 and Asp22, both about 4-5A
from the phenylalanine ring. This suggests some sort of binding site for an
inhibitor or activator, because no structural stability is possible from it, and the