5IQM

Crystal structure of the E. coli type 1 pilus subunit FimG (engineered variant with substitution Q134E; N-terminal FimG residues 1-12 truncated) in complex with the donor strand peptide DsF_T4R-T6R-D13N

Summary for 5IQM

• Entry DOI: 10.2210/pdb5iqm/pdb
• Descriptor: Protein FimG, Protein FimF, COBALT (II) ION, ... (4 entities in total)
• Functional Keywords: complex, protein, fimgt, cell adhesion
• Biological source: Escherichia coli K-12; More
• Cellular location: Fimbrium: P08190 P08189
• Total number of polymer chains: 4
• Total formula weight: 31071.30

Authors

Giese, C.,Eras, J.,Kern, A.,Scharer, M.A.,Capitani, G.,Glockshuber, R. (deposition date: 2016-03-11, release date: 2016-07-06, Last modification date: 2024-01-10)

Primary citation

Giese, C.,Eras, J.,Kern, A.,Scharer, M.A.,Capitani, G.,Glockshuber, R.
Accelerating the Association of the Most Stable Protein-Ligand Complex by More than Two Orders of Magnitude.
Angew.Chem.Int.Ed.Engl., 55:9350-9355, 2016

PubMed Abstract: The complex between the bacterial type 1 pilus subunit FimG and the peptide corresponding to the N-terminal extension (termed donor strand, Ds) of the partner subunit FimF (DsF) shows the strongest reported noncovalent molecular interaction, with a dissociation constant (KD ) of 1.5×10(-20)  m. However, the complex only exhibits a slow association rate of 330 m(-1)  s(-1) that limits technical applications, such as its use in affinity purification. Herein, a structure-based approach was used to design pairs of FimGt (a FimG variant lacking its own N-terminal extension) and DsF variants with enhanced electrostatic surface complementarity. Association of the best mutant FimGt/DsF pairs was accelerated by more than two orders of magnitude, while the dissociation rates and 3D structures of the improved complexes remained essentially unperturbed. A KD  value of 8.8×10(-22)  m was obtained for the best mutant complex, which is the lowest value reported to date for a protein/ligand complex.

PubMed: 27351462
DOI: 10.1002/anie.201603652

Experimental method

X-RAY DIFFRACTION (1.5 Å)