<prompt> True about Shiga toxin ?An endotoxinInhibit protein synthesisActivate adenylyl cyclaseIncrease cGMP  <response>: Ans. is b i.e., Inhibit protein synthesis Shiga toxin verocytotoxin It is an exotoxin. It is produced by shigella dysentriae type 1. Genes encoding shiga toxin are located on chromosome, while the VT1 of EHEC is phage-encoded. Toxin constits of two subunits - b Subunits, helps is binding and A subunit which has the active poion of toxin. Subunit A is divided into A, and A2 fragment. A l fragments inhibits protein synthesis by inactivating 60s ribosome. 