Identification of a heterologous cellulase and its N-terminus that can guide recombinant proteins out of Escherichia coli

Microbial Cell Factories

Research

Qingsheng Qi¹  Huili Yu¹  Shengjun Wang¹  Haoran Li¹  Dongfang Gao¹ 

[1] State Key Laboratory of Microbial Technology, Shandong University, 250100, Jinan, People’s Republic of China;

关键词: Escherichia coli;    Cellulase;    Extracellular protein production;    N-terminal sequence;   

DOI  :  10.1186/s12934-015-0230-8

 received in 2015-02-04, accepted in 2015-03-23,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundThe Gram-negative bacterium Escherichia coli has been widely used as a cell factory for the production of proteins and specialty chemicals because it is the best characterized host with many available expression and regulation systems. However, recombinant proteins produced in Escherichia coli are generally intracellular and often found in the form of inclusion bodies. Extracellular production of proteins is advantageous compared with intracellular production because extracellular proteins can be purified more easily and can avoid protease attack, which results in higher product quality. In this study, we found a catalytic domain of a cellulase (Cel-CD) and its N-terminus can be employed as carriers for extracellular production of recombinant proteins.ResultsIn this report, we identified the catalytic domain of a cellulase (Cel-CD) from Bacillus sp. that can be secreted into the medium from recombinant E. coli BL21 (DE3) in large quantities without its native signal peptide. By subcellular location analysis, we proved that the secretion was a two-step process and the N-terminal sequence of the full length Cel-CD played a crucial function in secretion. Both the Cel-CD and its N-terminal sequence can serve as carriers for efficient extracellular production of select target proteins.ConclusionsFusion of heterologous proteins with N20 from Cel-CD can carry the target proteins out of the cells with a concentration from 101 to 691 mg/L in flask cultivation. The extracellular recombinant proteins with a relative high purity. The results suggested that this system has a potential application in plant biomass conversion and industrial production of enzymes and therapeutic proteins.

【 授权许可】

Unknown   
© Gao et al.; licensee BioMed Central. 2015. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.