The putative fusion loop of PUUV G_C compared to fusion loops of other viral class II membrane fusion proteins.

(A) Structure-based multiple sequence alignment of the fusion loop regions from different class II members. Shading is in the same color scheme as in Fig 1. The PXD insertion in PUUV G_C is highlighted with a black box. Residues of PUUV G_C and RVFV G_C correspond to polyprotein precursor numbering. (B) Clockwise from the top left: PUUV G_C, RVFV G_C, DENV2 E and Semliki forest virus (SFV) E1 fusion loops (PDB codes 5J81, 4HJ1, 1OK8 and 1RER, respectively). The hydrophobic residues that anchor the protein to the cellular membrane are shown in stick representation and the disulfide bonds are shown in ball-and-stick representation. (C) CONSURF analysis [74] of unique hantavirus G_C sequences projected on the surface of PUUV sG_C crystal structure. A top view on the fusion loop, down the crystallographic tree-fold axis. The following uniprot (http://www.uniprot.org/) entries were used for the analysis: M9QRJ8, Q9QIZ1, M9QSR6, W5RRK8, Q5MYC0, Q9WJ31, Q2V8Y2, A0A068EN08, A0A0A7EQ65, Q66753, M9QY05, A0S5D7, O12371, Q9WSK6, Q806Y7, A0A0D5W3U2, F1T2C3, A8RRS6, G0WJH7, P27315, C7AGW1, B1NSM7, Q83887, A0A075IFP0, A0A0K0K9P4, Q9WMK6, A0A0F6T9U0, H8XZQ0, Q9DXJ5, Q9E158, Q91BQ9, A0A068ETZ4, A6MD75, B6DDK4, V9MFN9, H6WCQ9, Q99BV0, A0A077D3A4, P08668, F6KBJ3, A0RZG8, K4MYY7, R4JAI4, U5L2G2, O55348, H8ZHK6, H8ZHL5 (D) Hydrogen bond between W773 and the carbonyl of P781. Yellow dash line represents the distance between P781 carbonyl and W773.