鞘氨醇单胞菌PY3菲降解基因的克隆及序列分析

Cloning and Sequence Analysis of Phenanthrene Degradation Genes from Sphingomonas sp. Strain PY3

将菲降解菌鞘氨醇单胞菌 (Sphingomanassp .)PY3的DNA片段与pUC1 1 9质粒连接后 ,转化大肠杆菌JM1 0 9,经筛选得到两个质粒 ,分别命名为pUp1 (带有 2 3kb外源DNA片段 )和pUp2 (带有 3 9kb外源DNA片段 )。pUp 1的DNA含有 2个ORF。ORF 1由 2 75个氨基酸组成 ,与恶臭假单胞菌 (Pseudomonasputida)F1的甲苯水解酶及菌株PseudomonasCF6 0 0的甲苯水解酶在氨基酸水平上有 47%的同源性。ORF 2由 3 2 7个氨基酸组成 ,与嗜热脂肪芽孢杆菌(Bacillusstearothermophilus)的邻苯二酚双加氧酶 (pheB)及紫红红球菌 (Rhodococcusrhodochrous)CTM的邻苯二酚双加氧酶 (C2 3O)在氨基酸水平上分别有 5 7%和

The DNA fragment encoding %meta %-cleavage enzymes, involved in phenanthrene degradation, was cloned from the phenanthrene-degrading bacterium %Sphingomanas % sp. strains PY3. On the basis of restriction mapping analyses, these clones were classified into two types of plasmids, designated pUp 1(2 ^3 kb %Eco %RⅠ insert) and pUp 2(3 ^9 kb %Eco %RⅠ insert). DNA sequence analysis of 2 ^3-kb %Eco %RⅠ fragment revealed that were two open reading frames(ORF 1 and ORF 2). The deduced amino acid sequence of ORF 1 showed 47% identity with toluene hydrolase of %Pseudomonas putida % F1 and %Pseudomonas % CF600, respectively. The deduced amino acid sequence of ORF 2 showed 57 and 44% identity with catechol 2,3-dioxygenase(phe B) of %Bacillus stearothermophilus % and catechol 2,3-dioxygenase(C23O) of %Rhodococcus rhodochrous % CTM, respectively.