Related Experiment Video
Updated: Jul 19, 2026
07:08
Optimization of Synthetic Proteins: Identification of Interpositional Dependencies Indicating Structurally and/or Functionally Linked Residues
Published on: July 14, 2015
Computational basis of knowledge-based conformational probabilities derived from local- and long-range interactions
Lerzan Ormeci1, Attila Gursoy, Guzin Tunca
1College of Engineering, Koc University, Rumelifeneri Yolu, 34450 Sariyer, Istanbul, Turkey.
Proteins
|October 14, 2006
Summary
This study critically examines probabilities in Ramachandran maps, treating basins as rotational isomeric states. Modeling long-range correlations significantly improved predictions of helical and extended protein sequences.
Area of Science:
- Protein structure analysis
- Computational biology
- Biophysics
Background:
- Ramachandran maps are crucial for understanding protein backbone conformations.
- Probabilities within these maps are influenced by various factors, including residue correlations.
- Previous models often simplified or overlooked complex correlation effects.
Purpose of the Study:
- To critically evaluate probability calculations in Ramachandran map basins.
- To investigate the impact of statistical dependencies between residues on protein sequence predictions.
- To develop and test a method for modeling long-range correlations in protein sequences.
Main Methods:
- Analysis of Ramachandran map basins as rotational isomeric states.
- Calculation of singlet and pairwise dependent probabilities from protein libraries.
- Development of a method to evaluate long-range correlations, analogous to polymer theory.
- Construction of protein libraries excluding or including specific regions (coiled, helical, extended).
Main Results:
- Pairwise dependent probabilities did not outperform singlet probabilities in predicting sequence types.
- Modeling of long-range correlations significantly enhanced the accuracy of helical and extended sequence predictions.
- Excluding 'Chameleon' sequences improved predictive performance, though to a lesser extent than long-range correlation modeling.
Conclusions:
- Long-range correlations are critical for accurately predicting protein secondary structure (helical/extended) from sequence.
- Simple pairwise dependencies are insufficient for capturing these conformational preferences.
- Further refinement of models incorporating complex correlations is essential for advancing protein structure prediction.
Related Concept Videos
01:24Protein Organization
Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular transport, catalysis, and structural support. Proteins have a hierarchical structure comprising at least three levels of organization: primary, secondary, and tertiary structure. Some large proteins have a quaternary structure where individual protein subunits are linked together.
The primary structure of a protein is its amino acid sequence.
The primary structure of a protein is its amino acid sequence.
01:13Protein Organization
Overview
01:13Protein Organization
Overview
01:24Protein Organization
Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular transport, catalysis, and structural support. Proteins have a hierarchical structure comprising at least three levels of organization: primary, secondary, and tertiary structure. Some large proteins have a quaternary structure where individual protein subunits are linked together.
The primary structure of a protein is its amino acid sequence.
The primary structure of a protein is its amino acid sequence.
01:49Conserved Binding Sites
Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function.
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
01:49Conserved Binding Sites
Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function.
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...