Fig. 2
An elementary capsid C 1-subunit. a The linear sequences of the subunit. Antimicrobial (C 1 (+) strand) and antagonist (C 1 (−) strand) sequences are shown in blue and red, respectively, and are aligned under the coiled-coil heptad repeat pattern, gabcdef. The cysteine residue is shown in yellow. Crossed arrows show electrostatic interactions. Unengaged positively charged lysines are highlighted with “+”. These confer the dimer with an overall positive charge facilitating the binding of the subunit to anionic microbial membranes (see also Supplementary Table 1). b The sequences configured onto a coiled-coil helical wheel with 3.5 residues per turn. Curved double-headed arrows indicate electrostatic interactions between g and e′ (circled) residues. Crossed arrows show the hydrophobic interface of the dimeric subunit formed by isoleucines and leucines in a and d, respectively. c The linear sequence of the C 1 (+) strand. Monomeric (i, i + 7) and coiled-coil (i, i + 3 and i, i + 4) helical spacings are shown, one of each for clarity. d The sequence of the C 1 (+) strand configured onto a monomeric helical wheel with 3.6 residues per turn, showing the clustering of amino-acid residues into two distinctive polar and hydrophobic faces. e Molecular model of the coiled-coil C 1-subunit (PDB entry 4DMD, rendered by Macromodel Schrödinger). f The chemical structure of a dendrimer C 3-hub used to make the C 3-triskelion, C 3 (+) strand. βA denotes beta-alanine (see also Supplementary Fig 1)
