Improvement of dibenzothiophene desulfurization activity by removing the gene overlap in the dsz operon.
Dibenzothiophene (DBT) and its derivatives can be microbially desulfurized by Dsz enzymes. We investigated the expressional characteristics of the dsz operon. The result revealed that the ratio of mRNA quantity of dszA, dszB, and dszC was 11:3.3:1; however, western blot analysis indicated that the expression level of dszB is far lower than that of dszC. Gene analysis revealed that the termination codon of dszA and the initiation codon of dszB overlapped, whereas there was a 13-bp gap between dszB and dszC. In order to get a better, steady expression of DszB, we removed this structure by overlap polymerase chain reaction (PCR) and expressed the redesigned dsz operon in Rhodococcus erythropolis. The desulfurization activity of resting cells prepared from R. erythropolis DR-2, which held the redesigned dsz operon, was about five-fold higher than that of R. erythropolis DR-1, which held the original dsz operon.
Li
Guo-Qiang
GQ
College of Environment Sciences and Engineering, Nankai University, Tianjin, China.
Ma
Ting
T
Li
Shan-Shan
SS
Li
Hong
H
Liang
Feng-Lai
FL
Liu
Ru-Lin
RL
D015153:Blotting, Western; D009876:Operon / Q000235:genetics; D010105:Oxygenases / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D015202:Protein Engineering; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012240:Rhodococcus / Q000201:enzymology* / Q000235:genetics*; D013455:Sulfur / Q000378:metabolism*; D013876:Thiophenes / Q000378:metabolism*
D012333:RNA, Messenger; D011994:Recombinant Proteins; D013876:Thiophenes; D013455:Sulfur; D010105:Oxygenases; C421210:dibenzothiophene sulfone monooxygenase; C016366:dibenzothiophene