The sialoside-binding groove (Figure 5b,c) is formed by two loops, L1 consisting of 27-NDKDTG-32 and L2 consisting of 80-LKGSVLL-86 at the RBS edges, two hydrophobic pockets separated by the indole side chain of W90, P1 consisting of L85, L86 and W90 and P2 consisting of L80, W90 and F95 [193], and a residue, S87, interacting with L1 [92].