Figure 1.

(a) Most spikes are inclined to the local normal axis, as shown by the cryo-EM picture from Turoňová et al. (8). (b) Turoňová et al. (8) introduced the nomenclature of ankle, knee, and hip where most bending deformations are concentrated. (c) MD simulation of molecular structure of the S protein showing detailed features of α-helices and tropocollagen from Casalino et al. (12) and Yu et al. (11). (d) Overall geometry of the spike with a slender stalk and a solid head. The values of the main parameters were determined by averaging the dimension of the MD simulation taken from several most recent papers, mentioned in the above discussion, including Yu et al. (11). To see this figure in color, go online.