Fig. 8: The Sg7 protein family from Anopheles mosquitoes.
From: Mechanism of complement inhibition by a mosquito protein revealed through cryo-EM
a Amino acid alignment of Sg7-1 and Sg7-2 proteins from the Nyssorhynchus, Anopheles and Cellia subgenera of the genus Anopheles showing residues involved in C3bBb binding as identified for the albicin complex using PISA. Identities in the binding interface are shaded. Residues interacting with the C3b α-chain or both the α-chain and β-chain are shaded in red, those interacting with the β-chain alone are shaded in yellow, those interacting with the α-chain of the second monomer are shaded in green, and those interacting with FBb are shaded in cyan. b Superposition of Sg7-1 models from species representing the three major subgenera of Anopheles. The figure includes the crystal structures of albicin (PDB: 6XKE, light blue) from An. albimanus and SG7AF (PDB: 6XL7, copper) from An. freeborni (RMSD with albicin 0.71 Å over 96 Cα positions) along with models of Sg7-1 from An. atroparvus (magenta, RMSD with albicin 0.69 over 100 Cα positions) and An. stephensi (cyan, RMSD with albicin 0.84 Å over 109 Cα positions) generated with Alphafold 2. Disulfide bonds are shown as sticks with sulfur in yellow.
