Nucleotide sequence of plasmid pCNB1 from Comamonas strain CNB-1 reveals novel genetic organization and evolution for 4-chloronitrobenzene degradation

作者：Ma, Ying-Fei; Wu, Jian-Feng; Wang, Sheng-Yue; Jang, Cheng-Ying; Zhang, Yun; Qi, Su-Wei; Liu, Lei; Zhao, Guo-Ping^*; Liu, Shuang-Jiang

来源：Applied and Environmental Microbiology, 2007, 73(14): 4477-4483.

DOI：10.1128/AEM.00616-07

• PSEUDOMONAS-PSEUDOALCALIGENES JS45
• CATABOLIC PLASMID
• NITROBENZENE DEGRADATION
• ORGANIC-COMPOUNDS
• INITIAL REACTIONS
• PUTIDA
• TRANSPOSON
• ADAPTATION
• BACKBONE
• PATHWAY

The nucleotide sequence of a new plasmid pCNB1 from Comamonas sp. strain CNB-1 that degrades 4-chloronitrobenzene (4CNB) was determined. pCNB1 belongs to the IncP-1 beta group and is 91,181 bp in length. A total of 95 open reading frames appear to be involved in (i) the replication, maintenance, and transfer of pCNB1; (ii) resistance to arsenate and chromate; and (iii) the degradation of 4CNB. The 4CNB degradative genes and arsenate resistance genes were located on an extraordinarily large transposon (44.5 kb), proposed as TnCNB1. TnCNB1 was flanked by two IS1071 elements and represents a new member of the composite I transposon family. The 4CNB degradative genes within TnCNB1 were separated by various truncated genes and genetic homologs from other DNA molecules. Genes for chromate resistance were located on another transposon that was similar to the Tn21 transposon of the class II replicative family that is frequently responsible for the mobilization of mercury resistance genes. Resistance to arsenate and chromate were experimentally confirmed, and transcriptions of arsenate and chromate resistance genes were demonstrated by reverse transcription-PCR. These results described a new member of the IncP-1 beta plasmid family, and the findings suggest that gene deletion and acquisition as well as genetic rearrangement of DNA molecules happened during the evolution of the 4CNB degradation pathway on pCNB1.

• 出版日期2007-7
• 单位中国科学院上海生命科学研究院; 上海人类基因组研究中心; 中国科学院微生物研究所