이상엽 교수팀 (주저자: 나도균) 은 수개원 걸리던 미생물 세포공장 개발기간을 수일로 줄이는데 성공했다.세포 공장이란 미생물로 의학·산업용 유용 물질을 생산하는 시스템으로 이 기술이 상용화되면 미생물을 이용한 친환경 바이오 에너지와 의약품 생산이 대폭 확대될 전망이며, 본 연구결과는 "Nature Biotechnology" 1월20일자 인터넷판에 실렸다.
논문제목: Metabolic engineering of Escherichia coli using synthetic small regulatory RNAs
- Year published:(2013)DOI:doi:10.1038/nbt.2461Received17 January 2012 Accepted22 November 2012 Published online20 January 2013
- Figures left
Figure 1: Design principles for synthetic sRNAs.
(a) Mechanism of translation repression by sRNA. SD, Shine-Dalgarno sequence. (b) Scaffold selection process (Supplementary Figs. 1 and 2). C, no synthetic sRNA; −, scaffold without DsRed2-targeting sequence; +, scaffold with DsRed2-targeting sequence. Error bars, mean ± s.d. (c) The effect of binding region on repression efficiency. The letters denote binding sites of designed anti-DsRed2 synthetic sRNA variants (Supplementary Fig. 3). The location of TIR (green bar) was estimated using a previously published algorithm24. The intensity of DsRed2 that was not repressed by synthetic sRNAs was used as a control. All other intensities were normalized to the control. Error bars, mean ± s.d. (d) A quantitative relationship between synthetic sRNA binding energy and repression efficiency. Error bars, mean ± s.d. (e) The genetic structure of synthetic sRNA.T1/TE, transcriptional terminator (MITRegistry BBa_B0025). See Supplementary Figure 6 for full sequence of synthetic sRNAs.
Figure 2: Metabolic engineering of E. coli for the production of tyrosine using a synthetic sRNA strategy.
(a) The tyrosine biosynthetic pathway in E. coli. Overexpressed genes (green boxes) and synthetic sRNA translational repression targets (red boxes) are shown. PYR, pyruvate; PEP, phosphoenolpyruvate; F6P, fructose-6-phosphate; E4P, erythrose-4-phosphate; DAHP, 3-deoxy-D-arabino-heptulosonate 7-phosphate; SHIK, shikimate; S3P, shikimate 3-phosphate; CHA, chorismate; PPA, prephenate; TYR, tyrosine. Overexpressed feedback-resistant aroG and tyrA mutants are indicated (θ). Irrelevant reaction cascades are shown as dashed lines. (b) The plasmids used for gene amplification and sRNA-based repression. bla, beta-lactamase gene; kanR, kanamycin-resistance gene; Ptac, tac promoter; p15A, replication origin. (c) Tyrosine production in 14 different strains with different combinations of synthetic sRNAs. Anti-pgi-v1 and anti-pgi-v2 are variants of anti-pgi. They have different binding energies to pgi mRNA (Supplementary Fig. 12). (d) The effect of repression efficiency of anti-pgi sRNA variants on the growth profiles in strain S17-1 (producing the highest concentration of tyrosine) or in TOP10 (producing the lowest concentration). See Supplementary Figure 12 for detailed sequence information of anti-pgi-v1 and anti-pgi-v2. (e) Relative tyrosine production after fine-tuning of anti-csrA repression efficiency. Error bars, mean ± s.d. Tyrosine titers were normalized to the titer obtained from the engineered S17-1 strain which produced the highest concentration of tyrosine. Error bars, mean ± s.d.
Figure 3: Synthetic sRNA–based strategy for large-scale target identification and fine-tuning of gene expression for enhanced cadaverine production.