| Title | Functional characterization of the cutI gene for the transcription of carbon monoxide dehydrogenase genes in Mycobacterium sp. strain JC1 DSM 3803 |
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| Author | Jae Ho Lee1, Sae Woong Park1, Young Min Kim1, and Jeong-Il Oh2* |
| Address | 1Department of Systems Biology, Yonsei University, Seoul 03722, Republic of Korea, 2Department of Microbiology, Pusan National University, Busan 46241, Republic of Korea |
| Bibliography | Journal of Microbiology, 55(1),31-36, 2017, |
| DOI | 10.1007/s12275-017-6572-7 |
| Key Words | CO dehydrogenase, CutI, carboxydobacteria, Mycobacterium sp. strain JC1, nitric oxide |
| Abstract | Carbon monoxide dehydrogenase (CO-DH) in Mycobacterium sp. strain JC1 is a key enzyme for the carboxydotrophic growth, when carbon monoxide (CO) is supplied as a sole source of carbon and energy. This enzyme is also known to act as nitric oxide dehydrogenase (NO-DH) for the detoxification of NO. Several accessory genes such as cutD, cutE, cutF, cutG, cutH, and cutI, are clustered together with two copies of the CO-DH structural genes (cutB1C1A1 and cutB2C2A2) in Mycobacterium sp. strain JC1 and are well conserved in carboxydotrophic mycobacteria. Transcription of the CO-DH structural and accessory genes was demonstrated to be increased significantly by acidified sodium nitrate as a source of NO. A cutI deletion (ΔcutI) mutant of Mycobacterium sp. strain JC1 was generated to identity the function of CutI. Lithoautotrophic growth of the ΔcutI mutant was severely affected in mineral medium supplemented with CO, while the mutant grew normally with glucose. Western blotting, CO-DH activity staining, and CO-DH-specific enzyme assay revealed a significant decrease in the cellular level of CO-DH in the ΔcutI mutant. Northern blot analysis and promoter assay showed that expression of the cutB1 and cutB2 genes was significantly reduced at the transcriptional level in the ΔcutI mutant, compared to that of the wildtype strain. The ΔcutI mutant was much more susceptible to NO than was the wild type. |