The most well studied type of DE is the AU-rich element (ARE) AUUUA, found in the 3’ UTR of up to 8% of mammalian mRNAs

#Id: 2557

#Unit 13. Methods in Biology

The light-absorbing/ emitting center of GFP (its chromophore) comprises an oxidized form of the tripeptide –Ser65–Tyr66–Gly67

#Id: 2558

#Unit 13. Methods in Biology

This protein, from the bioluminescent jellyfish  Aequorea victoria, fluoresces with a peak wavelength of 508 nm (green light) when irradiated by ultraviolet or blue light (optimally 400 nm).

#Id: 2559

#Unit 13. Methods in Biology

Cyclization between Ser and Gly is probably rapid, and the oxidation of the Tyr side chain (by O2) is probably the rate-limiting step of fluorophore generation.

#Id: 2560

#Unit 13. Methods in Biology

Genetic engineering has introduced site-specific mutations that enhance fluorescence intensity and shift the wavelength of the emitted light to different colors, thereby making it possible to simultaneously monitor the expression of two or more different genes.

#Id: 2561

#Unit 13. Methods in Biology

An excited fluorescent molecule such as GFP or YFP can dispose of the energy from the absorbed photon in either of two ways: 

by fluorescence, emitting a photon of slightly longer wavelength (lower energy) than the exciting light, or 

by nonradiative fluorescence resonance energy transfer (FRET).

#Id: 2562

#Unit 13. Methods in Biology

FRET is inversely proportional to the sixth power of the distance between donor and acceptor.