MMAR_2770, a new enzyme involved in biotin biosynthesis, is essential for the growth of Mycobacterium marinum in macrophages and zebrafish.
Biotin, which functions as an essential cofactor for certain carboxylases and decarboxylases, is synthesized by a multistep pathway in microorganisms and plants. Biotin biosynthesis has not been studied in detail in mycobacteria. In this study, we isolated a mutant of Mycobacterium marinum in which MMAR_2770, a previously uncharacterized gene encoding a predicted short-chain dehydrogenase/reductase, was inactivated. We found that this mutant is a biotin auxotroph that cannot grow in a minimal medium (Sauton) unless biotin is supplemented. Complementation of the mutant with an intact MMAR_2770 or its homolog Rv1882c of Mycobacterium tuberculosis restored the growth of the mutant, suggesting that MMAR_2770 is involved in biotin biosynthesis. We further showed that the mutant was unable to grow in cultured macrophages and was attenuated in zebrafish. Taken together, our results demonstrate that biotin biosynthesis is essential for the growth of mycobacteria in vitro and in vivo and have provided validation for targeting biotin biosynthetic enzymes for antimycobacterial drug development. The potential role of MMAR_2770 in mycobacterial biotin biosynthesis is discussed.
Key Laboratory of Medical Molecular Virology, Institute of Biomedical Sciences and Medical Microbiology, Fudan University, 138 Yi Xue Yuan Road, Shanghai, China.
Jia
J
Yu
Chen
C
Niu
Decheng
D
Wang
Ming
M
Li
Woeishyang
W
Teo
Gang
G
Sun
Jianping
J
Wang
Jun
J
Liu
Qian
Q
Gao
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001710:Biotin / Q000096:biosynthesis; D002460:Cell Line; D008264:Macrophages / Q000382:microbiology*; D051379:Mice; D009154:Mutation; D009165:Mycobacterium Infections, Nontuberculous / Q000201:enzymology* / Q000382:microbiology* / Q000473:pathology; D019910:Mycobacterium marinum / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D015027:Zebrafish / Q000382:microbiology*
D001426:Bacterial Proteins; D001710:Biotin