Neurotoxin gene clusters in Clostridium botulinum type A strains:: Sequence comparison and evolutionary implications
Neurotoxin gene clusters in Clostridium botulinum type A strains:: Sequence comparison and evolutionary implications
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DOI：
10.1007/s00284-002-3851-1
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发表时间：
2003-05-01
影响因子：
2.6
通讯作者：
Johnson, EA
中科院分区：
文献类型：
--
作者：
Dineen, SS;Bradshaw, M;Johnson, EA
测定了A型肉毒梭菌62A中血凝素（ha）基因和转录调节因子botR基因的核苷酸序列，测定了Hall A-hyper中肉毒杆菌神经毒素（BoNT）基因簇的完整核苷酸序列。BoNT/A基因簇的比较显示两个菌株之间只有两个核苷酸差异。在菌株62A、Hall A-hyper和A(B)型NCTC 2916中也测定了BoNT集群两侧区域的核苷酸序列。A型菌株BoNT/A集群的上游区域与A(B)菌株沉默BoNT/B集群的上游区域具有显著的同源性，表明相似的进化起源。在A型菌株中，BoNT/A集群的下游区域编码具有多个内部突变的假定插入序列（IS）元件。这些IS元素可能在宿主基因组和其他梭状芽胞杆菌物种的神经毒素基因转移中发挥了作用。
The nucleotide sequence of the hemagglutinin (ha) genes and the transcriptional regulator botR gene were determined in type A Clostridium botulinum strain 62A, and the complete nucleotide sequence of the botulinum neurotoxin (BoNT) gene cluster was determined in strain Hall A-hyper. Comparison of the BoNT/A gene clusters revealed only two nucleotide differences between the two strains. The nucleotide sequences of the regions flanking the BoNT clusters were also determined in strains 62A, Hall A-hyper, and type A(B) strain NCTC 2916. The regions upstream of the BoNT/A clusters in the type A strains shared marked homology with the region upstream of the silent BoNT/B cluster in the A(B) strain, indicating a similar evolutionary origin. The region downstream of the BoNT/A cluster in type A strains encodes putative insertion sequence (IS) elements with multiple internal mutations. These IS elements may have played a role in neurotoxin gene transfer within the host genome and to other Clostridium species.