Organization of the botulinum neurotoxin C1 gene and its associated non-toxic protein genes in Clostridium botulinum C 468.
A 12.3 kb DNA fragment encompassing the botulinum neurotoxin C1 (BoNT/C1) gene and an upstream flanking region was sequenced from Clostridium botulinum C 468 phage 1C. The resulting bont/C1 locus includes six genes which are organized into three transcriptional units. Cluster 1 encompasses the bont/C1 gene and an upstream gene encoding a non-toxic protein associated with the toxin (Antp139/C1). Transcriptional analysis revealed that these two genes form an operon; the bont/C1 gene can be transcribed alone or co-transcribed with antp139/C1. Cluster 2 encompasses three genes (antp33/C1, antp17/C1 and antp70/C1), which also form an operon. The corresponding proteins are similar to components of the hemagglutinin complex associated with BoNT/A and BoNT/B of C. botulinum A and B. In addition, Antp33/C1 is identical to HA-33, an hemagglutinin encoded by C. botulinum C-Stockholm phage C-St; Antp70/C1 displays some relatedness to C. perfringens enterotoxin. The third transcriptional unit consists of orf-22, which encodes a basic protein showing 29% identity with the gene product of uviA, a plasmid-encoded protein of 22 kDa which has been identified as a positive regulator of the bacteriocin production in C. perfringens. Orf-22 could be an effector controlling the expression of the bont/C1 and its antp genes in C. botulinum C 468.
Unité des Toxines Microbiennes, Institut Pasteur, Paris, France.
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D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001435:Bacteriophages / Q000235:genetics; D001483:Base Sequence; D001905:Botulinum Toxins / Q000235:genetics*; D003001:Cloning, Molecular; D003014:Clostridium botulinum / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009498:Neurotoxins / Q000235:genetics*; D016366:Open Reading Frames / Q000235:genetics; D009876:Operon / Q000235:genetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D009498:Neurotoxins; D012333:RNA, Messenger; D001905:Botulinum Toxins