title: Use of bacterial two-hybrid system to investigate the molecular interaction between the regulators NifA and NifL of Enterobacter cloacae.
abstract: Expression of the nitrogen fixation (nif) genes is tightly regulated by two proteins NifA and NifL in the gamma-subdivision of the proteobacteria. NifA is a transcriptional activator, which can be inactivated by NifL in the presence of oxygen or excess fixed nitrogen. A direct interaction between E. cloacae NifL and NifA was detected using the bacterial two-hybrid system. This interaction was accelerated in the presence of fixed nitrogen, while oxygen had no effect. NifL proteins, with their C-terminus being deleted, completely lost the ability to interact with NifA. The data suggest that the C-terminal domain of NifL acts as a sensor of the nitrogen status of the cell and mediates interaction with NifA.
authors.affiliation: Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, China.
authors.forename: Gongxian
authors.initials: G
authors.lastname: Liao
authors.forename: Guanqiao
authors.initials: G
authors.lastname: Yu
authors.forename: Shanjiong
authors.initials: S
authors.lastname: Shen
authors.forename: Jiabi
authors.initials: J
authors.lastname: Zhu