2F47

Xray crystal structure of T4 lysozyme mutant L20/R63A liganded to methylguanidinium

Summary for 2F47

• Entry DOI: 10.2210/pdb2f47/pdb
• Descriptor: Lysozyme, CHLORIDE ION, 1-METHYLGUANIDINE, ... (5 entities in total)
• Functional Keywords: molecular switch, t4 lysozyme, nano-bitechnology, protein engineering, protein design, hydrolase
• Biological source: Enterobacteria phage T4
• Cellular location: Host cytoplasm : P00720
• Total number of polymer chains: 1
• Total formula weight: 19872.22

Authors

Yousef, M.S.,Bischoff, N.,Dyer, C.M.,Baase, W.A.,Matthews, B.W. (deposition date: 2005-11-22, release date: 2006-04-25, Last modification date: 2023-08-23)

Primary citation

Yousef, M.S.,Bischoff, N.,Dyer, C.M.,Baase, W.A.,Matthews, B.W.
Guanidinium derivatives bind preferentially and trigger long-distance conformational changes in an engineered T4 lysozyme.
Protein Sci., 15:853-861, 2006

PubMed Abstract: The binding of guanidinium ion has been shown to promote a large-scale translation of a tandemly duplicated helix in an engineered mutant of T4 lysozyme. The guanidinium ion acts as a surrogate for the guanidino group of an arginine side chain. Here we determine whether methyl- and ethylguanidinium provide better mimics. The results show that addition of the hydrophobic moieties to the ligand enhances the binding affinity concomitant with reduction in ligand solubility. Crystallographic analysis confirms that binding of the alternative ligands to the engineered site still drives the large-scale conformational change. Thermal analysis and NMR data show, in comparison to guanidinium, an increase in protein stability and in ligand affinity. This is presumably due to the successive increase in hydrophobicity in going from guanidinium to ethylguanidinium. A fluorescence-based optical method was developed to sense the ligand-triggered helix translation in solution. The results are a first step in the de novo design of a molecular switch that is not related to the normal function of the protein.

PubMed: 16600969
DOI: 10.1110/ps.052020606

Experimental method

X-RAY DIFFRACTION (1.7 Å)