1.C.4.7.1
The Bin binary toxin, BinAB.  BinA is a toxic P42 protein (protein of 42 KDa) of 362 aas.  The 3-d structure of BinB (448 aas; 1.75 Å resolution) is available; it has two domains, an N-terminal sugar-binding lectin-like domain, and a C-terminal aerolysin-like β-barrel pore-forming domain. Although it shows low sequence identity with other members of the family, it is a member of the Aerolysin Family (Srisucharitpanit et al. 2014).  Protoxin subunits only form monomers, but in vitro activated toxin forms heterodimers. Maximal toxicity to mosquito larvae is achieved when the two subunits, BinA and BinB, are in a 1:1 molar ratio (Surya et al. 2016). An aromatic residue cluster in the C-terminal domain of BinB is critical for toxin insertion in membranes (Chooduang et al. 2018).