Poster abstracts

Poster number 13 submitted by Nicholas Callahan

Algorithm for screening consensus mutations

Nicholas Callahan (Dept. of Chemistry and Biochemistry, Ohio State University), Sidharth Mohan (Dept. of Chemistry and Biochemistry, Ohio State University), Kimberly Stephany (Dept. of Chemistry and Biochemistry, Ohio State University), Eva Petrik (Dept. of Chemistry and Biochemistry, Ohio State University), Brandon Sullivan (Dept. of Chemistry and Biochemistry, Ohio State University), Thomas Magliery (Dept. of Chemistry and Biochemistry, Ohio State University)

Abstract:
Consensus mutations have been a powerful tool in the search for stabilized variants of protein folds. The use of consensus is complicated when the evolutionary history of individual sequences is not reflected in the total consensus. Recent work by the Magliery lab has demonstrated the utility of filtering potential consensus mutations for residues with high evidence of co-evolution, thereby preventing the disruption of residue interactions unique to the target sequence’s evolutionary history. This approach yielded a variant of yeast triosphosphate isomerase (TIM) with a higher melting temperature than an unfiltered consensus mutant. Based on this work, we have created a consensus-screening algorithm and applied it to a variety of proteins – adenylate kinase (ADK) from B. subtilis and E. coli; TIM from yeast, human, and E. coli; and the DNA binding domain of fructose repressor (FruR) from E. coli. Here we present melting temperatures and activities for our algorithm variants, which have been generated using alignments of different phylogenetic character. Our results demonstrate the applicability of our approach to different folds, as well as reaffirm the importance of proper alignment curation to avoid contradiction between universal consensus and specific variants.

Keywords: consensus design, bioinformatics, protein engineering