1Q4A

S65T Q80R Green Fluorescent Protein (GFP) pH 8.5

Summary for 1Q4A

• Entry DOI: 10.2210/pdb1q4a/pdb
• Related: 1Q4B 1Q4C 1Q4D 1Q4E 1Q73
• Descriptor: Green Fluorescent Protein (2 entities in total)
• Functional Keywords: green fluorescent protein, gfp, fluorophore, chromophore, luminescent protein
• Biological source: Aequorea victoria
• Total number of polymer chains: 1
• Total formula weight: 26945.38

Authors

Jain, R.K.,Ranganathan, R. (deposition date: 2003-08-02, release date: 2004-02-03, Last modification date: 2024-11-20)

Primary citation

Jain, R.K.,Ranganathan, R.
Local complexity of amino acid interactions in a protein core.
Proc.Natl.Acad.Sci.USA, 101:111-116, 2004

PubMed Abstract: Atomic resolution structures of proteins indicate that the core is typically well packed, suggesting a densely connected network of interactions between amino acid residues. The combinatorial complexity of energetic interactions in such a network could be enormous, a problem that limits our ability to relate structure and function. Here, we report a case study of the complexity of amino acid interactions in a localized region within the core of the GFP, a particularly stable and tightly packed molecule. Mutations at three sites within the chromophore-binding pocket display an overlapping pattern of conformational change and are thermodynamically coupled, seemingly consistent with the dense network model. However, crystallographic and energetic analyses of coupling between mutations paint a different picture; pairs of mutations couple through independent "hotspots" in the region of structural overlap. The data indicate that, even in highly stable proteins, the core contains sufficient plasticity in packing to uncouple high-order energetic interactions of residues, a property that is likely general in proteins.

PubMed: 14684834
DOI: 10.1073/pnas.2534352100

Experimental method

X-RAY DIFFRACTION (1.45 Å)