The R-type pyocin of Pseudomonas aeruginosa C is a bacteriophage tail-like particle that contains single-stranded DNA
The R-type pyocin of Pseudomonas aeruginosa C is a bacteriophage tail-like particle that contains single-stranded DNA
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DOI：
10.1128/iai.67.2.717-725.1999
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发表时间：
1999-02-01
影响因子：
3.1
通讯作者：
Apicella, MA
中科院分区：
文献类型：
--
作者：
Lee, FKN;Dudas, KC;Apicella, MA
铜绿假单胞菌r型脓毒素颗粒被描述为类似噬菌体尾状结构的细菌素。由于它们不寻常的结构，我们重新检查了它们是否含有核酸。我们的数据表明，从铜绿假单胞菌C （pyocin C）中分离的pyocin颗粒含有DNA。通过随机引物延伸法将该DNA生成的探针杂交到限制性内切酶酶切铜绿假单胞菌C基因组DNA的不同条带上。这些探针还与产生r型脓毒杆菌的18株铜绿假单胞菌中6株的基因组DNA杂交。非对称PCR、互补寡核苷酸杂交和电镜分析表明，pyocin C颗粒含有封闭的环状单链DNA，长度约为4.0 kb。对丝裂霉素c诱导培养的细胞内DNA进行检查，发现存在两个染色体外DNA分子，一个双链分子和一个单链分子，它们与pyocin DNA杂交。对含有pyocin DNA的P. aeruginosa C染色体DNA的7480个核苷酸序列分析表明，存在与丝状噬菌体和隐匿噬菌体元件相似的pyocin开放阅读框。我们没有观察到与已知的噬菌体结构蛋白或先前表征的表达r型脓毒蛋白结构蛋白的假单胞体prt基因有任何相似之处。这些研究表明，来自铜绿假单胞菌C的脓毒素颗粒是含有新的封闭环状单链DNA的缺陷噬菌体，该DNA来自铜绿假单胞菌C的染色体。
Pseudomonas aeruginosa R-type pyocin particles have been described as bacteriocins that resemble bacteriophage tail-like structures. Because of their unusual structure, we reexamined whether they contained nucleic acids. Our data indicated that pyocin particles isolated from P. aeruginosa C (pyocin C) contain DNA. Probes generated from this DNA by the random-primer extension method hybridized to distinct bands in restriction endonuclease-digested P. aeruginosa C genomic DNA. These probes also hybridized to genomic DNA from 6 of 18 P. aeruginosa strains that produced R-type pyocins. Asymmetric PCR, complementary oligonucleotide hybridization, and electron microscopy indicated that pyocin C particles contained closed circular single-stranded DNA, approximately 4.0 kb in length. Examination of total intracellular DNA from mitomycin C-induced cultures revealed the presence of two extrachromosomal DNA molecules, a double-stranded molecule and a single-stranded molecule, which hybridized to pyocin DNA. Sequence analysis of 7,480 nucleotides of P. aeruginosa C chromosomal DNA containing the pyocin DNA indicated the presence of pyocin open reading frames with similarities to open reading frames from filamentous phages and cryptic phage elements. We did not observe any similarities to known phage structural proteins or previously characterized pseudomonal prt genes expressing R-type pyocin structural proteins. These studies demonstrate that pyocin particles from P. aeruginosa C are defective phages that contain a novel closed circular single-stranded DNA and that this DNA was derived from the chromosome of P. aeruginosa C.