True about Shiga toxin ?
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.
An endotoxin
Inhibit protein synthesis
Activate adenylyl cyclase
Increase cGMP