8XC6

Crystal structure of large stokes shift red fluorescent protein tKeima

Summary for 8XC6

• Entry DOI: 10.2210/pdb8xc6/pdb
• Descriptor: fluorescent protein (1 entity in total)
• Functional Keywords: native, fluorescent protein
• Biological source: Montipora sp. 20
• Total number of polymer chains: 2
• Total formula weight: 50795.59

Authors

Nam, K.H. (deposition date: 2023-12-08, release date: 2024-04-17, Last modification date: 2024-10-09)

Primary citation

Nam, K.H.,Xu, Y.
Structural Analysis of the Large Stokes Shift Red Fluorescent Protein tKeima.
Molecules, 29:-, 2024

PubMed Abstract: The Keima family comprises large Stokes shift fluorescent proteins that are useful for dual-color fluorescence cross-correlation spectroscopy and multicolor imaging. The tKeima is a tetrameric large Stokes shift fluorescent protein and serves as the ancestor fluorescent protein for both dKeima and mKeima. The spectroscopic properties of tKeima have been previously reported; however, its structural basis and molecular properties have not yet been elucidated. In this study, we present the crystallographic results of the large Stokes shift fluorescent protein tKeima. The purified tKeima protein spontaneously crystallized after purification without further crystallization. The crystal structure of tKeima was determined at 3.0 Å resolution, revealing a β-barrel fold containing the Gln-Tyr-Gly chromophores mainly with cis-conformation. The tetrameric interfaces of tKeima were stabilized by numerous hydrogen bonds and salt-bridge interactions. These key residues distinguish the substituted residues in dKeima and mKeima. The key structure-based residues involved in the tetramer formation of tKeima provide insights into the generation of a new type of monomeric mKeima. This structural analysis expands our knowledge of the Keima family and provides insights into its protein engineering.

PubMed: 38893454
DOI: 10.3390/molecules29112579

Experimental method

X-RAY DIFFRACTION (3 Å)