PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 21630488-2 2011 The holotoxin is composed of two polypeptide chains linked by a single disulfide bond: the A-chain (RTA), which is an N-glycosidase enzyme, and the B-chain (RTB), a lectin polypeptide that binds galactosyl moieties on the surface of the mammalian target cells. stichoposide 4-13 RNA binding fox-1 homolog 2 Homo sapiens 100-103 28398250-2 2017 This is because the ribosome binding site of the ricin A chain (RTA) is blocked by the B subunit in ricin holotoxin. stichoposide 106-115 RNA binding fox-1 homolog 2 Homo sapiens 64-67