Figure 2. Location of the Leu113Ser mutation in the crystal structure of the NT-4-TrkB complex. The two chains of the dimeric NT-4 are in cyan and blue, respectively. The alpha carbon of the mutated residue is shown as a magenta sphere, with the prime symbol denoting the residue of the second subunit. TrkB domains are shown in orange and red color. The Leu113 residue is located close to the TrkB binding site.