Gluconobacter oxydans may contain an incomplete phosphoenolpyruvate: carbohydrate phosphotransferase system consisting of three components - EI, HPr and EIIA, while the function of individual members of the system remains unknown. In this research, a specific interaction between EI and a histidine kinase-response regulator hybrid protein was screened by yeast two-hybrid assay, and the interaction was further identified with GST pull-down assay and bimolecular fluorescence complementation assay in vitro and in vivo, respectively. As the histidine kinase-response regulator hybrid protein serves as a member of two-component system in G. oxydans, its interaction with El implied that PTS may play certain roles in bacteria under stress. (C) 2016 Elsevier Inc. All rights reserved.