A new algorithm for the alignment of multiple protein structures using Monte Carlo optimization

C Guda1, E D Scheeff, P E Bourne

  • 1San Diego Supercomputer Center, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0537, USA.

Insights

A new Monte Carlo algorithm enhances multiple protein structure alignment by improving alignment scores by 69% and incorporating more residue positions. This method preserves crucial catalytic residues in protein families.

Area of Science:

  • Computational Biology
  • Structural Bioinformatics
  • Biochemistry

Background:

  • Multiple protein structure alignment is crucial for understanding protein function and evolution.
  • Existing methods may not fully capture complex structural relationships.
  • Accurate alignment is essential for identifying conserved regions and functional sites.

Purpose of the Study:

  • To develop and evaluate a novel algorithm for multiple protein structure alignment.
  • To improve the accuracy and completeness of protein structural alignments.
  • To provide a robust tool for analyzing protein structural families.

Main Methods:

  • Development of a Monte Carlo optimization technique for structural alignment.
  • Utilizing pair-wise structural alignments as initial input.
  • Implementing four distinct move types for random alignment modifications.
  • Employing a distance-based scoring system for move acceptance/rejection.
  • Convergence criteria based on alignment score improvement.

Main Results:

  • Demonstrated significant improvement in alignment scores (69% average increase) across 66 protein structural families.
  • Increased the number of aligned residue positions by 12%.
  • Successfully aligned protein kinases and aspartic proteinases, outperforming existing curated and manual alignments.
  • Preserved key catalytic residues in tested protein families.

Conclusions:

  • The developed Monte Carlo algorithm offers a significant advancement in multiple protein structure alignment.
  • The method enhances alignment quality by increasing aligned residues and improving scores while maintaining functional site integrity.
  • Future work includes refining the algorithm for broader application across the Protein Data Bank (PDB).

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