Structural determination of Streptococcus pyogenes M1 protein interactions with human immunoglobulin G using integrative structural biology
Fig 5
H-bond network between the M1 peptides and IgG Fc-domain.
The residues forming H-bond contacts between the (a) M1(A)-IgG(Fc) and (b) M1(S)-IgG(Fc) are shown with spheres. The thickness of the yellow lines corresponds to the persistence of the interactions throughout the replicates of MD simulations. The M1 peptide is colored in gray while the chains of the IgG Fc-domain are depicted in red and pink. The distribution of distances between the residues forming H-bond contacts along the MD simulations are shown for the (c) M1(A)-IgG(Fc) and (d) M1(S)-IgG(Fc). The number of replicates in which, the H-bonds are formed for at least 40% of the simulation time are added in red at the top of each box. Communication Blocks (CBspath) identified by COMMA2 are mapped on the structure of (e) M1(A)-IgG(Fc), and (f) M1(S)-IgG(Fc). Distinct CBspath of four residues or more are highlighted in different colors. The isolated communication pathway between the M1 peptide A-domain (T110) and IgG Fc-domain (E263) is depicted by a black line on the corresponding structure.