Fig. 3.

Analysis of the drNurA-HerA interaction interface. A The protein interaction interface between drNurA and the HAS-barrel domains of drHerA. The subunits of drHerA and drNurA are labeled and highlighted in distinct colors. The surface around the drNurA-HerA interface is extracted from the real density of the cryo-EM data obtained in this study. B The zoom in view of the drNurA-HerA interaction interface. Different protomers are colored differently. The carbon atoms on the Cα backbone of residues which might be essential for interactions, are shown as spheres and colored according to their electrostatic potential (basic residues are colored blue and acidic residues are colored red). C Electrostatic properties of drNurA and drHerA. The electrostatic potentials of drNurA and drHerA were calculated separately with APBS and mapped onto the solvent-accessible surface of the structure at contouring levels of ±5 kT (blue/red). D Gel filtration analysis of the drNurA-HerA complex formation. The drNurA-HerA mixture was analyzed with Superdex S200 HR 10/300 column. Input drHerA and drNurA were in a molar ratio of 2:1. Peaks of each injection were reconstructed using GraphPad Prism software. Fractions eluted were resolved by 12% SDS-PAGE. HerA^m, HerA with point mutations D78A, E80A, and D81A; NurA^m1, NurA with point mutations H89A and R92A; NurA^m2, NurA with point mutations R117A, R121A, and H124A; NurA^m3, NurA with point mutations K299A, K303A, H305A, and K306A; NurA^m4, NurA with point mutations R336A, R337A, and R339A