Schmitt J, Karalewitz A, Benefield DA, Mushrush DJ, Pruitt RN, Spiller BW, Barbieri JT, Lacy DB. Structural analysis of botulinum neurotoxin type G receptor binding . Biochemistry. 2010 Jun 29;49(49). 5200-5. PMID: 20507178 [PubMed] PMCID: PMC2894633 NIHMSID: NIHMS210255.
Botulinum neurotoxin (BoNT) binds peripheral neurons at the neuromuscular junction through a dual-receptor mechanism that includes interactions with ganglioside and protein receptors. The receptor identities vary depending on BoNT serotype (A-G). BoNT/B and BoNT/G bind the luminal domains of synaptotagmin I and II, homologous synaptic vesicle proteins. We observe conditions under which BoNT/B binds both Syt isoforms, but BoNT/G binds only SytI. Both serotypes bind ganglioside G(T1b). The BoNT/G receptor-binding domain crystal structure provides a context for examining these binding interactions and a platform for understanding the physiological relevance of different Syt receptor isoforms in vivo.