Nucleotide sequence of plasmid pCNB1 from comamonas strain CNB-1 reveals novel genetic organization and evolution for 4-chloronitrobenzene degradation.
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-1beta 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-1beta 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.
Ma
Ying-Fei
YF
State Key Laboratory of Microbial Resource at Institute of Microbiology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing 100080, People's Republic of China.
Wu
Jian-Feng
JF
Wang
Sheng-Yue
SY
Jiang
Cheng-Ying
CY
Zhang
Yun
Y
Qi
Su-Wei
SW
Liu
Lei
L
Zhao
Guo-Ping
GP
Liu
Shuang-Jiang
SJ
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001149:Arsenates / Q000494:pharmacology; D001483:Base Sequence; D001673:Biodegradation, Environmental; D002840:Chromates / Q000494:pharmacology; D020585:Comamonas / Q000235:genetics* / Q000378:metabolism; D004261:DNA Replication / Q000235:genetics; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D015870:Gene Expression; D023061:Gene Order; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D008969:Molecular Sequence Data; D009578:Nitrobenzenes / Q000378:metabolism*; D016366:Open Reading Frames; D010957:Plasmids / Q000235:genetics*; D012329:RNA, Bacterial / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D016415:Sequence Alignment; D014158:Transcription, Genetic
D000900:Anti-Bacterial Agents; D001149:Arsenates; D002840:Chromates; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D009578:Nitrobenzenes; D012329:RNA, Bacterial; D012333:RNA, Messenger; C010407:4-chloronitrobenzene; C025657:arsenic acid