Adaptive evolution of bat dipeptidyl peptidase 4 (dpp4): implications for the origin and emergence of Middle East respiratory syndrome coronavirus

Abstract
The newly emerged Middle East respiratory syndrome coronavirus (MERS-CoV) that first appeared in Saudi Arabia during the summer of 2012 has to date (20th September 2013) caused 58 human deaths. MERS-CoV utilizes the dipeptidyl peptidase 4 (DPP4) host cell receptor, and analysis of the long-term interaction between virus and receptor provides key information on the evolutionary events that lead to the viral emergence.