What is a key feature of GFP (green fluorescent protein)?

The key feature of green fluorescent protein (GFP) is the presence of amino acids that are buried at the center of the protein structure. This characteristic plays a crucial role in the protein's stability and function.

GFP exhibits a unique beta-barrel structure, which is instrumental in creating a protective environment for the chromophore—the part of the protein responsible for its fluorescence. The central cavity of the beta-barrel is where the chromophore resides, and the hydrophobic environment formed by the amino acids that are buried in the center shields it from the surrounding aqueous environment. This sequestration is vital for the fluorescent properties of GFP since it minimizes quenching effects from water molecules and other potential interfering substances.

In contrast, options relating to the N-terminus and nucleophilic reactions involving tyrosine do not accurately depict the defining structural features of GFP. Additionally, while hydrophobic bonds do contribute to the overall stabilization of many proteins, the specific emphasis on the arrangement of amino acids in the center is what highlights GFP's unique structural characteristic. Thus, the proper understanding of GFP hinges notably on recognizing the significance of the buried amino acids in the core of the protein.