Mutual Information-Based Cliques of Amino Acids in the Zaire Ebola Virus-Makona Glycoprotein

The Zaire Ebola virus Makona variant (ZEBOV-Makona) is the cause of the 2014-2015 high-mortality epidemic of Ebola virus disease (EVD). The viral glycoprotein (GP) mediates cell binding and internalization of the virus. Information entropy (H) determined on ZEBOV-Makona GP sequences (downloaded 6/18/2015) isolated from humans with EVD identified three amino positions (82, 230 and 371) with H values significantly greater than those of all the other 673 GP amino acids. These three large H value amino acid positions served as reference positions for detection of three disjoint, complete but non-interconnected MI-based cliques of amino acids. These three cliques contained subsets of five, ten and six amino acids, respectively. Fifteen of the cliqued amino acids were in random coils, four in helices and two in extended sheets. However, the following metadata applied to all 21 of the MI-cliqued GP amino acids: each wild type, cliqued amino acid was of one of the essential amino acids VAL, THR or ILE. Since the essential amino acids are not synthesized by humans, use of these essential amino acids by the MI-based cliques may reflect host factors, e.g., diet and nutritional status. that influence occurrence and survival of the ZEBOV-Makona GP mutations.