Figure 4.

Schematic of crystal structure. (A) Orientations relative to the long crystal axis (c–c′) of: major dipole for fluorophores (f–f′), slow birefringence axis (s–s′), and β can major axis (b–b′). (B) Published structure of GFP molecule based on x-ray crystallographic analyses (6, 7). (C) Schematic array of molecules fitting conditions shown in A and B. While maintaining the parallel alignment of the chromophore ellipsoids' major axes, this schematic could be modified with the backbone of the β cans rotated around the long crystal axis to occupy two or more discrete orientations.