The dye of red fluorescent protein.
The two rings are co-planar. That makes it a good 'storage ring' (excuse le mot)
for energetic states.
The biggest difference between green fluorescent protein and it's red
analog, DsRed, is that the chromophore of DsRed has an extra double bond
(drawn in yellow) which extends the chromophores conjugation and causes
the red-shift:
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The dye of red fluorescent protein. |