Study of correlation between protein sequence similarity and organisms optimal growth temperature

HERNÁNDEZ BERTHET, AYELÉN S.; APTEKMANN, ARIEL A.; GONZÁLEZ LEBRERO, RODOLFO M.; NOGUERA, MARTIN E.; ROMAN, ERNESTO A.

San Luis

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Biofísica; 2019

Structural and functional information of proteins are codified in their amino acid sequences. Within a protein family, there are proteins that come from different kinds of organisms: some growth at high temperatures (termophiles), some at middle (mesophiles) and others at low temperatures (psychrophiles). Usually occurs that optimal protein function temperature (OPFT) is close to the optimal growth temperature (OGT) of the organisms that come from. These behaviour is reflected in the sequence differences between orthologs that could affect their function, stability and conformational flexibility. But which of these are more associated to the OGTs? Is there any region more coupled than others? In this work we seek to study the sequences of an Archaea?s database tocompare the differences between these sequences and the OGT.To this end, we aligned the sequences of Adenylate kinase, SPT5 elongation factor and Copper-exporting P-type ATPase protein families. Then we compared each possible pair of sequences and quantify their differences, using different substitution matrices. We made comparisons in windows of different size throughout the alignment, or taking positions near in space (using a representative structure of the family as a reference) or taking combinations of random positions of the alignment. Then we made a linear fit ofthe data and analyzed the correlation?s coefficient ( R ) and Pearson?s significance (p). We obtained values of R for each family and analyze those that outliers of more than two or three standard deviations from the average. We obtained positions of significant correlation for each family, and compared the correlation of these positions with bibliographic data.We found that in the studied families are positions or combinations that have positive correlation with the organisms OGT. Our preliminary results suggest that upon refinement, this method may be used to predict the OGT of a given organism only from sequence data.AcknowldegmentsWith grants from ANPCyT, CONICET and UBA