Overexpression of a pathway specific negative regulator enhances production of daunorubicin in bldA deficient Streptomyces peucetius ATCC 27952.
The dnrO gene is the first regulator to be activated in the daunorubicin (DNR) biosynthesis pathway of Streptomyces peucetius ATCC 27952. DnrO is known for its self-repression capability while it activates rest of the DNR biosynthesis pathway through cascades of regulatory events. S. peucetius was found to contain no functional copy of bldA-tRNA while a detailed examination of dnrO codons reveals the presence of TTA codon, which is rarely encoded by bldA-tRNA. Therefore, for evaluating the role of dnrO in DNR production, multiple engineered strains of S. peucetius were generated by heterologously expressing bldA, dnrO and combination of bldA and dnrO. Using these strains, the effects of heterologously expressed bldA and overexpressed dnrO were evaluated on pathway specific regulators, mycelial densities and production of DNR. The results showed that the transcription level of dnrO and master regulator dnrI, was found to be elevated in bldA containing strain in comparison to dnrO overexpressed strain. The bldA containing strain produces 45.7% higher DNR than bldA deficient wild type strain from culture broth with OD600 of 1.45 at 72h. Heterologous expression of bldA-tRNA is accounted for increased transcription levels of the DNR pathway specific regulators and enhanced DNR production.
Department of Life Science and Biochemical Engineering, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, Republic of Korea.
Anaya Raj
AR
Pokhrel
Department of Life Science and Biochemical Engineering, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, Republic of Korea.
Amit Kumar
AK
Chaudhary
Department of Life Science and Biochemical Engineering, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, Republic of Korea.
Hue Thi
HT
Nguyen
Department of Life Science and Biochemical Engineering, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, Republic of Korea.
Dipesh
D
Dhakal
Department of Life Science and Biochemical Engineering, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, Republic of Korea.
Tuoi Thi
TT
Le
Department of Life Science and Biochemical Engineering, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, Republic of Korea.
Anil
A
Shrestha
Department of Life Science and Biochemical Engineering, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, Republic of Korea; Department of BT-Convergent Pharmaceutical Engineering, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, Republic of Korea.
Kwangkyoung
K
Liou
Department of Life Science and Biochemical Engineering, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, Republic of Korea; Department of BT-Convergent Pharmaceutical Engineering, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, Republic of Korea. Electronic address: sohng@sunmoon.ac.kr.
Jae Kyung
JK
Sohng
D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000235:genetics*; D002851:Chromatography, High Pressure Liquid; D003062:Codon; D003577:Cytochrome P-450 Enzyme System / Q000172:deficiency*; D003630:Daunorubicin / Q000096:biosynthesis* / Q000737:chemistry; D015870:Gene Expression; D053858:Metabolic Networks and Pathways; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003062:Codon; C096749:DnrQ protein, Streptomyces peucetius; D003577:Cytochrome P-450 Enzyme System; D003630:Daunorubicin
Daunorubicin; Regulatory genes; Streptomyces