Restriction map of the 125-kilobase plasmid of Bacillus thuringiensis subsp israelensis carrying the genes that encode delta-endotoxins active against mosquito larvae
Restriction map of the 125-kilobase plasmid of Bacillus thuringiensis subsp israelensis carrying the genes that encode delta-endotoxins active against mosquito larvae
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DOI：
10.1128/aem.62.9.3140-3145.1996
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发表时间：
1996-09-01
影响因子：
4.4
通讯作者：
Zaritsky, A
中科院分区：
文献类型：
--
作者：
BenDov, E;Einav, M;Zaritsky, A
从苏云金芽孢杆菌以色列亚种中分离到一个含有全部β-内毒素基因的大质粒，含有BamHI、EcoRI、HindIII、KpnI、PstI、SacI和SalI的限制性内切酶；并在大肠杆菌中克隆为合适的文库，筛选含有BamHI、SacI和Sail识别位点的插入片段，每个插入片段用P-32标记并与凝胶的Southern blotts杂交，这些片段是用几个限制性内切酶切割产生的片段，以对齐相关酶的至少两个片段，所有9个BamHI片段和所有8个SacI片段被定位在两个重叠的连锁群中(总大小分别约为76和56kb)，一些片段之间的同源性明显是转座子和重复插入序列存在的结果。四个Delta-内毒素基因(CryIVB-D和CyTA)和两个调节多肽基因(分别为19和20 kDa)定位在质粒的21kb片段上；如果没有CyTA，它们被放置在单个BamHI片段上，这种融合使Delta-内毒素基因(不包括CryIVA，定位在另一个连接基上)作为一个完整的自然片段进行亚克隆。
A large plasmid containing all delta-endotoxin genes was isolated from Bacillus thuringiensis subsp, israelensis; restricted by BamHI, EcoRI, HindIII, KpnI, PstI, SacI, and SalI; and cloned as appropriate libraries in Escherichia coli, The libraries were screened for inserts containing recognition sites for BamHI, SacI, and Sail, Each was labeled with P-32 and hybridized to Southern blots of gels with fragments generated by cleaving the plasmid with several restriction endonucleases, to align at least two fragments of the relevant enzymes, All nine BamHI fragments and all eight SacI fragments were mapped in two overlapping linkage groups (with total sizes of about 76 and 56 kb, respectively), The homology observed between some fragments is apparently a consequence pf the presence of transposons and repeated insertion sequences. Four delta-endotoxin genes (cryIVB-D and cytA) and two genes for regulatory polypeptides (of 19 and 20 kDa) were localized on a 21-kb stretch of the plasmid; without cytA, they are placed on a single BamHI fragment, This convergence enables subcloning of delta-endotoxin genes (excluding cryIVA, localized on the other linkage group) as an intact natural fragment.