Limpanawat Suweeraya, Promdonkoy Boonhiang, Boonserm Panadda
Institute of Molecular Biosciences, 25/25 Phuttamonthon 4 Road, Salaya, Phuttamonthon, Nakhon Pathom, 73170, Thailand.
Curr Microbiol. 2009 Nov;59(5):509-13. doi: 10.1007/s00284-009-9468-x. Epub 2009 Aug 13.
The binary toxin (Bin) from Bacillus sphaericus consists of two polypeptides, BinA (42 kDa) and BinB (51 kDa) that work together to kill susceptible mosquito larvae. To investigate the functional regions of BinA involved in the interaction with BinB, four BinA truncated fragments, from both N- and C- termini, were constructed and expressed in Escherichia coli. Neither individual nor a mixture of fragments of BinA showed larvicidal activity against Culex quinquefasciatus larvae even using a high dose of toxins. Far-Western dot blot analysis showed strong binding of both C-terminal fragments (17 and 28 kDa) to BinB protein. This is the first report to demonstrate that the C-terminal part of BinA plays an important role for the interaction with BinB.
球形芽孢杆菌的二元毒素（Bin）由两种多肽组成，即BinA（42 kDa）和BinB（51 kDa），它们共同作用杀死易感蚊虫幼虫。为了研究BinA中参与与BinB相互作用的功能区域，构建了来自N端和C端的四个BinA截短片段，并在大肠杆菌中表达。即使使用高剂量的毒素，BinA的单个片段或片段混合物对致倦库蚊幼虫均未显示杀幼虫活性。Far-Western斑点印迹分析表明，两个C端片段（17 kDa和28 kDa）均与BinB蛋白有强烈结合。这是首次证明BinA的C端部分在与BinB相互作用中起重要作用的报告。
