Interaction between PII and NifA in Azospirillum brasilense Sp7

The interaction between PinII and NifA in A. brasilense Sp7 was investigated by using the yeast two-hybrid system. Our experimental results showed that PinII directly interacted with the entire NifA protein and its N-terminal domain, but did not interact with the central domain and the C-terminal domain of NifA. No interaction happened if glnB coding for PinII was frame-shift mutated. Pz, a homolog of PinII, had no interation with NifA.