We carry out a comprehensive study of long-range interactions on a large data set of non-homologous proteins. Our study reveals that the long-range interactions between amino acids far apart are common in protein folding, and play an important role on the formation of secondary structure. Using residue-wise contact order(RWCO) to describe long-range interactions, we further evaluate the effect of long-range interactions on secondary structure prediction. We select six most popular prediction methods and collect their prediction results on the same set of proteins. All the six prediction methods show a significant negative correlation between prediction accuracy and RWCO. Key words: Long-range interactions, protein secondary structure, mutual information, residue-wise contact order, correlation coefficient.
Jinmiao Chen, Narendra S. Chaudhari