Complete nucleotide sequence and organization of the atrazine catabolic plasmid pADP-1 from Pseudomonas sp. strain ADP
Complete nucleotide sequence and organization of the atrazine catabolic plasmid pADP-1 from Pseudomonas sp. strain ADP
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DOI：
10.1128/jb.183.19.5684-5697.2001
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发表时间：
2001-10-01
影响因子：
3.2
通讯作者：
Sadowsky, MJ
中科院分区：
文献类型：
--
作者：
Martinez, B;Tomkins, J;Sadowsky, MJ
假单胞菌裂解质粒PADP-1的108,845个核苷酸全序列。测定了菌株ADP。前人发现，pADP-1编码AtzA、AtzB和AtzC，催化除草剂阿特拉津中的S-三氮杂环取代基的一系列水解反应生成三聚氰酸。计算分析表明，PADP-1编码104个可能的开放阅读框架(ORF)，这些ORF被预测在分解代谢、转座、以及质粒的维持、转移和复制中发挥作用。编码PADP-1转移和复制功能的区域与以前从产气肠杆菌中分离到的IncPβ质粒pR751具有80%~100%的氨基酸序列同源性。PADP-1含有一个功能性抗汞操纵子，与Tn5053有99%的同源性。鉴定出与IS1071的TnpA和假单胞菌产碱假单胞菌的TnpA具有99%氨基酸序列同源性的转座酶的完整拷贝，并分别位于atzA、atzB和atzC基因的两侧，形成类似于嵌套分解代谢转座子的结构。功能分析确定了三个新的分解代谢基因atzD、atze和atzF，它们参与阿特拉津的分解代谢。表达AtzD的大肠杆菌粗提物将三聚氰酸水解成缩二脲。AtzD与假单胞菌TrzD(三聚氰酸氨基水解酶)的氨基酸序列同源性为58%。菌株NRRLB-12227。另外两个编码三聚氰酸进一步分解代谢的基因atze和atzF位于一个毗邻潜在LysR型转录调控因子的连续簇中。携带atze和atzF的大肠埃希菌分别编码缩二脲水解酶和尿磷酸盐水解酶。AtzDEF是共转录的。Atze和AtzF是一个共同的酰胺酶蛋白家族的成员。这些数据揭示了分解代谢质粒的完整结构，并表明阿特拉津分解代谢基因分布在质粒的三个不同区域。这些结果开始深入了解质粒是如何结构的，从而进化为编码最近添加到生物圈的化合物的分解代谢。
The complete 108,845-nucleotide sequence of catabolic plasmid pADP-1 from Pseudomonas sp. strain ADP was determined. Plasmid pADP-1 was previously shown to encode AtzA, AtzB, and AtzC, which catalyze the sequential hydrolytic removal of s-triazine ring substituents from the herbicide atrazine to yield cyanuric acid. Computational analyses indicated that pADP-1 encodes 104 putative open reading frames (ORFs), which are predicted to function in catabolism, transposition, and plasmid maintenance, transfer, and replication. Regions encoding transfer and replication functions of pADP-1 had 80 to 100% amino acid sequence identity to pR751, an IncP beta plasmid previously isolated from Enterobacter aerogenes. pADP-1 was shown to contain a functional mercury resistance operon with 99% identity to Tn5053. Complete copies of transposases with 99% amino acid sequence identity to TnpA from IS1071 and TnpA from Pseudomonas pseudoalcaligenes were identified and flank each of the atzA, atzB, and atzC genes, forming structures resembling nested catabolic transposons. Functional analyses identified three new catabolic genes, atzD, atzE, and atzF, which participate in atrazine catabolism. Crude extracts from Escherichia coli expressing AtzD hydrolyzed cyanuric acid to biuret. AtzD showed 58% amino acid sequence identity to TrzD, a cyanuric acid amidohydrolase, from Pseudomonas sp. strain NRRLB-12227. Two other genes encoding the further catabolism of cyanuric acid, atzE and atzF, reside in a contiguous cluster adjacent to a potential LysR-type transcriptional regulator. E. coli strains bearing atzE and atzF were shown to encode a biuret hydrolase and allophanate hydrolase, respectively. atzDEF are cotranscribed. AtzE and AtzF are members of a common amidase protein family. These data reveal the complete structure of a catabolic plasmid and show that the atrazine catabolic genes are dispersed on three disparate regions of the plasmid. These results begin to provide insight into how plasmids are structured, and thus evolve, to encode the catabolism of compounds recently added to the biosphere.