Fig. 5.

Application for an infectious clone of MERS-CoV expressing tRFP. (a) Genomic representation of an infectious clone of MERS-CoV containing the tomato red fluorescent protein (tRFP) substituted for the orf 5 gene (icMERS-CoV-tRFP). (b) Protein sequence alignment of human, mouse, and chimeric dipeptidyl peptidase 4 ( DPP4) MERS-CoV host receptor sequence with five specific amino acid changes indicated by red arrows. Figure reprinted from [40]. (c) The indicated chimeric DPP4 receptor constructs were overexpressed in 293T cells and subsequently infected with the icMERS-CoV-tRFP virus to map the minimal number of amino acids required to facilitate MERS-CoV infection. Two amino acid changes (A288L and T330R) were sufficient to support infection and replication of MERS-CoV . Figure reprinted from [40]