Transposon-Like Organization of the Plasmid-Borne Organophosphate Degradation (opd) Gene Cluster Found in Flavobacterium sp
Transposon-Like Organization of the Plasmid-Borne Organophosphate Degradation (opd) Gene Cluster Found in Flavobacterium sp
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DOI：
10.1128/aem.69.5.2533-2539.2003
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发表时间：
2003-05
影响因子：
4.4
通讯作者：
D. Siddavattam;S. Khajamohiddin;B. Manavathi;S. Pakala;M. Merrick
中科院分区：
文献类型：
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作者：
D. Siddavattam;S. Khajamohiddin;B. Manavathi;S. Pakala;M. Merrick
摘要从不同地理区域采集的土壤样品中分离出几种可以利用有机磷农药作为碳源的细菌菌株。所有这些生物体都合成一种叫做谷胱甘肽水解酶的酶，在每种情况下，这种酶都是由位于一个大的固有质粒上的基因（opd）编码的。这些质粒显示出相当大的遗传多样性，但含有opd基因的区域是高度保守的。两种opd质粒，来自黄杆菌属的pPDL 2和来自缺陷假单胞菌的pCMS 1，被很好地表征，并且在它们中的每一个中，含有opd基因的约5.1kb的区域显示出相同的限制性图谱。我们现在报告质粒pPDL 2保守区的完整序列。opd基因的上游侧接插入序列ISFlsp 1，ISFlsp 1是IS 21家族的成员，下游侧接编码转座酶和解离酶的Tn3样元件。与opd相邻但以相反方向转录的是开放阅读框（orf 243），其具有编码有点类似于恶臭假单胞菌TodF的芳香族水解酶的潜力。我们已经表明，orf243编码的多肽的27 kDa，这在对硝基苯酚的降解中发挥作用，并可能在演唱会与opd的降解中发挥作用。opd和orf243的连锁，opd侧翼基因的组织，以及这些基因的广泛地理分布表明，该DNA序列可能构成一个复杂的分解代谢转座子。
ABSTRACT Several bacterial strains that can use organophosphate pesticides as a source of carbon have been isolated from soil samples collected from diverse geographical regions. All these organisms synthesize an enzyme called parathion hydrolase, and in each case the enzyme is encoded by a gene (opd) located on a large indigenous plasmid. These plasmids show considerable genetic diversity, but the region containing the opd gene is highly conserved. Two opd plasmids, pPDL2 from Flavobacterium sp. and pCMS1 from Pseudomonas diminuta, are well characterized, and in each of them a region of about 5.1 kb containing the opd gene shows an identical restriction pattern. We now report the complete sequence of the conserved region of plasmid pPDL2. The opd gene is flanked upstream by an insertion sequence, ISFlsp1, that is a member of the IS21 family, and downstream by a Tn3-like element encoding a transposase and a resolvase. Adjacent to opd but transcribed in the opposite direction is an open reading frame (orf243) with the potential to encode an aromatic hydrolase somewhat similar to Pseudomonas putida TodF. We have shown that orf243 encodes a polypeptide of 27 kDa, which plays a role in the degradation of p-nitrophenol and is likely to act in concert with opd in the degradation of parathion. The linkage of opd and orf243, the organization of the genes flanking opd, and the wide geographical distribution of these genes suggest that this DNA sequence may constitute a complex catabolic transposon.