Fig. 6

Structural prediction of native PERV-C(5683) (KY352351.2) and HA-tagged PERV-C(5683) variants. Structures were predicted using AlphaFold2 [46] and compared using a MUSCLE alignment. PERV-C(5683) is colored in dark gray and PERV-C(5683)-HA variants are shown in light gray. Major sequence motifs are color-coded SP (green), VRA (light blue), VRB (dark blue), PRR (purple), and RPep (yellow). The HA-tag is colored in red. A Comparison and alignment of PERV-C(5683) and SP-HA. AI Whole proteins. AII Detailed view of predicted structural changes. Insertion of the HA-tag in SP-HA resulted in a shift of the PRR (left) and the formation of an additional alpha helix adjacent to SP (right). B Comparison and alignment of PERV-C(5683) and HA-VRA. (B I), whole proteins. (B II), detailed view of predicted structural changes. A twist in the PRR was observed in HA-VRA, resulting in a compressed loop compared with PERV-C(5683) (left). In addition, an intrinsically twisted loop was formed by the HA-tag (right). C Comparison and alignment of PERV-C(5683) and RPep. CI Whole proteins. CII Detailed view of predicted structural changes. RPep-HA shows a slightly shifted structure compared with PERV-C(5683). The main differences are in the SP, PRR (left) and RPep (right) and are indicated by arrow. pLDDT scores are shown in Additional file 3: Fig. S3