7VNL

Sandercyanin mutant-F55A-Biliverdin complex

Summary for 7VNL

• Entry DOI: 10.2210/pdb7vnl/pdb
• Descriptor: Sandercyanin Fluorescent Protein, BILIVERDINE IX ALPHA, TETRAETHYLENE GLYCOL, ... (4 entities in total)
• Functional Keywords: lipocalin, biliverdin, fluorescent protein
• Biological source: Sander vitreus (walleye)
• Total number of polymer chains: 2
• Total formula weight: 41721.05

Authors

Yadav, K.,Ghosh, S.,Subramanian, R. (deposition date: 2021-10-11, release date: 2022-05-25, Last modification date: 2024-10-30)

Primary citation

Yadav, K.,Ghosh, S.,Barak, A.,Schaefer, W.,Subramanian, R.
Phenylalanine stacking enhances the red fluorescence of biliverdin IX alpha on UV excitation in sandercyanin fluorescent protein.
Febs Lett., 596:796-805, 2022

PubMed Abstract: Biliverdin IXα (BV) binds to several prokaryotic and eukaryotic proteins. How nature exploits the versatility of BV's properties is not fully understood. Unlike free BV, the Sandercyanin fluorescent protein bound to BV (SFP-BV) shows enhanced red fluorescence (675 nm) on excitation in the UV region (380 nm). Site-directed mutagenesis showed that the BV complex of two SFP variants, F55A and E79A, resulted in the loss of red fluorescence. Crystal structures of the complexes of these proteins with BV show the absence of stacking interactions of the F55 phenyl ring with BV. BV changes from ZZZssa conformation in the wild-type to ZZZsss conformation in the variants. In the nonfluorescent mutants, the lowest excited state is destabilized, resulting in nonradiative decay.

PubMed: 35020202
DOI: 10.1002/1873-3468.14281

Experimental method

X-RAY DIFFRACTION (1.93 Å)