FIG 5.

Sequencing of the contemporary isolate, BR-18. (A, top) The E1/E2 amino acids that make contact with the receptor MXRA8 are identical for the two MAYV isolates, showing 60% amino acid identity with CHIKV (Reunion Island isolate). (Bottom) The crystal structure of CHIKV E1/E2 dimer, with the receptor contact residues that differed between MAYV and CHIKV colored as above. (B, top) Differences between the two MAYV isolates in E1/E2 (these amino acids are believed not to be involved in interaction with the receptor). (Bottom) The crystal structure of CHIKV E1/E2 dimer, with the residues that differed between the two isolates colored as above.