H2r: Identification of evolutionary important residues by means of an entropy based analysis of multiple sequence alignments

Background: A multiple sequence alignment (MSA) generated for a protein can be used to characterise residues by means of a statistical analysis of single columns. In addition to the examination of individual positions, the investigation of co-variation of amino acid frequencies offers insights into function and evolution of the protein and residues. Results: We introduce conn(k), a novel parameter for the characterisation of individual residues. For each residue k, conn(k) is the number of most extreme signals of co-evolution. These signals were deduced from a normalised mutual information (MI) value U(k, l) computed for all pairs of residues k, l. We demonstrate that conn(k) is a more robust indicator than an individual MI-value for the prediction of residues most plausibly important for the evolution of a protein. This proposition was inferred by means of statistical methods. It was further confirmed by the analysis of several proteins. A server, which computes conn(k)-values is ava...

• Type: Journal
• Year: 2008
• Where: BMCBI
• Authors: Rainer Merkl, Matthias Zwick
• Keywords: BMCBI 2008, Individual Residues, Multiple Sequence Alignment, Protein