Pathway optimization by re-design of untranslated regions for L-tyrosine production in Escherichia coli.
L-tyrosine is a commercially important compound in the food, pharmaceutical, chemical, and cosmetic industries. Although several attempts have been made to improve L-tyrosine production, translation-level expression control and carbon flux rebalancing around phosphoenolpyruvate (PEP) node still remain to be achieved for optimizing the pathway. Here, we demonstrate pathway optimization by altering gene expression levels for L-tyrosine production in Escherichia coli. To optimize the L-tyrosine biosynthetic pathway, a synthetic constitutive promoter and a synthetic 5'-untranslated region (5'-UTR) were introduced for each gene of interest to allow for control at both transcription and translation levels. Carbon flux rebalancing was achieved by controlling the expression level of PEP synthetase using UTR Designer. The L-tyrosine productivity of the engineered E. coli strain was increased through pathway optimization resulting in 3.0 g/L of L-tyrosine titer, 0.0354 g L-tyrosine/h/g DCW of productivity, and 0.102 g L-tyrosine/g glucose yield. Thus, this work demonstrates that pathway optimization by 5'-UTR redesign is an effective strategy for the development of efficient L-tyrosine-producing bacteria.
School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 790-784, Korea.
Seong Cheol
SC
Kim
Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 790-784, Korea.
Byung Eun
BE
Min
School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 790-784, Korea.
Hyun Gyu
HG
Hwang
Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 790-784, Korea.
Sang Woo
SW
Seo
School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 790-784, Korea.|Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 790-784, Korea.
Gyoo Yeol
GY
Jung
D053898:Biosynthetic Pathways; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial; D060847:Metabolic Engineering; D050743:Pyruvate Synthase / Q000235:genetics / Q000378:metabolism; D014443:Tyrosine / Q000096:biosynthesis*; D020506:Untranslated Regions
D029968:Escherichia coli Proteins; D020506:Untranslated Regions; D014443:Tyrosine; D050743:Pyruvate Synthase; C506224:ppsA protein, E coli