Figure 4 - full size

 

Figure 4.
Ribbon diagram of the crystal structures of the wild-type protein and the GST50H mutant. The rainbow color-coding represents the B value distribution of the backbone atoms of the structures (blue = low B values, red = high B values). In the crystal structures, the highest conformational flexibility is observed in Helix B. The average B value for the main-chain atoms of this structural segment averages to about B = 60 A^2 (see also Fig. 7 Figure 7-). With the introduction of a histidine at position 50, the mobility of this helix is dramatically increased by almost a factor of 2 (see also Fig. 7 Figure 7-). Despite this structural flexibility, the affinity of this mutant to bind GSH has increased dramatically as well. The corresponding density of the substrate was clearly visible in the electron density maps and could be refined to full occupancy.

The above figure is reprinted from an Open Access publication published by the Protein Society: Protein Sci (2009, 18, 217-228) copyright 2009.