Fig. 2.

Overlapping specific structural effects of the T203C, Y145C, and ΔpH mutations. Bar graphs (a–c) and colorimetric representations (d–f) of the magnitude of displacement of atoms in the mutant structures T203C (a and d), Y145C (b and e), and ΔpH (c and f) relative to wild type. Δr_norm is the raw atomic displacements weighted by the propagated errors in atomic centroids (see Materials and Methods). (a–c) Atom numbers are in order of PDB file format, and peaks are labeled with the corresponding amino acid position. (d–f) Cross-sections within the core of GFP to display the chromophore region. T203C shows a directional pattern of structural change connecting position 203 with the surface of the β-barrel, whereas Y145C shows an isotropic pattern of change limited to the immediate vicinity that overlaps with the effects of T203C. The global perturbation of ΔpH shows two regions of structural change that are widely separated in the molecule; one of these is nearly the same as for T203C.