Skip to main content
. 2011 Nov 15;81:85–164. doi: 10.1016/B978-0-12-385885-6.00009-2

Figure 6.

Figure 6

A speculative evolutionary history of the lectin activity of HE and S proteins. S proteins that maintain the ability to hemaggultinate and bind to glycans are denoted S+; those that have lost this ability as S−. For SARS-CoV, hemagglutinating activity has not been reported and to our knowledge has not been tested for; this is denoted as S? HE proteins with a requirement or a strong preference for 9-O-acetyl sialic acid as their ligand (and esterase substrate) are depicted as HE+. HE proteins from strains of MHV where the preferred ligand (substrate) of HE is 4-O-acetyl sialic acid are depicted as HE + *. This schema is supported by the presence of hemagglutinin (lectin-like) activity of TGEV (an alphacoronavirus) (Krempl et al., 2000) and IBV (a gammacoronavirus) (Niesters et al., 1987), and the presence of a galectin fold in the receptor-binding domain of MHV (Peng et al., 2011).