Related Experiment Video
Updated: Jul 11, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
Strain in protein structures as viewed through nonrotameric side chains: II. effects upon ligand binding
1Division of Mathematical Biology, National Institute for Medical Research, London, United Kingdom. jhering@nimr.mrc.ac.uk
Abstract:
The relation between the spatial positioning of nonrotameric residues and ligands was studied in 112 tertiary structures of protein-ligand complexes with a crystallographic resolution of = 1. 8 A. Nonrotameric side chains and especially clusters of interacting nonrotameric residues were found to be associated preferentially with ligand- and substrate-binding sites. Asp, Glu, His, Met, and Asn are favored nonrotameric residue types positioned in the first 9-A shell around ligands. Comparison of 20 complexes with associated apo structures suggests that ligand binding induces nonrotamericity and, hence, strain within protein-ligand complexes. The internal energy gain is not neutralized by increased hydrogen bonding or salt-bridge formation involving side chains that become nonrotameric in the complexed structure. It is suggested that the increased internal energy might aid in the formation and ejection of enzymatic products, thereby enhancing activity. These results could prove useful in protein engineering experiments aimed at altering enzymatic activity. Proteins 1999;37:44-55.
Related Concept Videos
Protein Folding
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme can...
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Ligand Binding and Linkage
Protein Folding
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...

