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Updated: Jun 19, 2026
09:51
Investigating Protein Sequence-structure-dynamics Relationships with Bio3D-web
Published on: July 16, 2017
Conformation dependence of backbone geometry in proteins
Donald S Berkholz1, Maxim V Shapovalov, Roland L Dunbrack
1Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA.
Structure (London, England : 1993)
|October 20, 2009
Summary
Protein backbone geometry is not fixed; it changes with conformation. This study defines these variations, improving protein structure prediction and refinement accuracy.
Area of Science:
- Structural Biology
- Computational Biology
- Biophysics
Background:
- The traditional view assumes a single, ideal peptide backbone geometry in proteins.
- This assumption, however, is an oversimplification, as quantum mechanics and empirical data suggest geometry varies with protein conformation.
Purpose of the Study:
- To challenge the existing paradigm by defining conformation-dependent variations in protein backbone covalent geometry.
- To provide a more accurate model for protein structure determination and predictive modeling.
Main Methods:
- Analysis of a nonredundant dataset of ultrahigh-resolution protein structures.
- Identification and quantification of systematic variations in bond lengths and angles based on phi and Psi dihedral angles.
Main Results:
- Demonstrated that protein backbone covalent geometry systematically varies with dihedral angles.
- Established a rational structural basis for these variations, including atomic clash avoidance and electrostatic interactions.
- Developed a conformation-dependent library of covalent geometry, outperforming existing methods in accuracy.
Conclusions:
- The paradigm of a single, context-independent ideal protein backbone geometry is incorrect.
- Incorporating conformation-dependent covalent geometry significantly improves the accuracy of protein structure refinement and predictive modeling.
- The developed library offers a practical tool for advancing protein structure research.
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