Conversion of an inactive xylose isomerase into a functional enzyme by co-expression of GroEL-GroES chaperonins in Saccharomyces cerevisiae

BMC Biotechnology

Research Article

Juliana José¹  Victor Augusti Negri¹  Juliana Pimentel Galhardo¹  Marcelo Falsarella Carazzolle¹  Pedro Henrique Mello Magalhães¹  Cidnei Marschalk¹  Beatriz Temer¹  Thamy Lívia Ribeiro Corrêa¹  Leandro Vieira dos Santos²  Gonçalo Amarante Guimarães Pereira² 

[1] Laboratory of Genomics and Expression, Department of Genetics and Evolution, Institute of Biology, UNICAMP, Campinas, 13083-970, São Paulo, Brazil;Laboratory of Genomics and Expression, Department of Genetics and Evolution, Institute of Biology, UNICAMP, Campinas, 13083-970, São Paulo, Brazil;CTBE – Brazilian Bioethanol Science and Technology Laboratory, Campinas, SP, Brazil;

关键词: Xylose isomerase;    Saccharomyces cerevisiae;    Xylose fermentation;    GroEL-GroES chaperonins;    Ethanol production;   

DOI  :  10.1186/s12896-017-0389-7

 received in 2017-03-07, accepted in 2017-08-18,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundSecond-generation ethanol production is a clean bioenergy source with potential to mitigate fossil fuel emissions. The engineering of Saccharomyces cerevisiae for xylose utilization is an essential step towards the production of this biofuel. Though xylose isomerase (XI) is the key enzyme for xylose conversion, almost half of the XI genes are not functional when expressed in S. cerevisiae. To date, protein misfolding is the most plausible hypothesis to explain this phenomenon.ResultsThis study demonstrated that XI from the bacterium Propionibacterium acidipropionici becomes functional in S. cerevisiae when co-expressed with GroEL-GroES chaperonin complex from Escherichia coli. The developed strain BTY34, harboring the chaperonin complex, is able to efficiently convert xylose to ethanol with a yield of 0.44 g ethanol/g xylose. Furthermore, the BTY34 strain presents a xylose consumption rate similar to those observed for strains carrying the widely used XI from the fungus Orpinomyces sp. In addition, the tetrameric XI structure from P. acidipropionici showed an elevated number of hydrophobic amino acid residues on the surface of protein when compared to XI commonly expressed in S. cerevisiae.ConclusionsBased on our results, we elaborate an extensive discussion concerning the uncertainties that surround heterologous expression of xylose isomerases in S. cerevisiae. Probably, a correct folding promoted by GroEL-GroES could solve some issues regarding a limited or absent XI activity in S. cerevisiae. The strains developed in this work have promising industrial characteristics, and the designed strategy could be an interesting approach to overcome the non-functionality of bacterial protein expression in yeasts.

【 授权许可】

CC BY   
© The Author(s). 2017