Helicobacter pylori hydrogenase accessory protein HypA and urease accessory protein UreG compete with each other for UreE recognition

► Two different optical biosensing methods were used (biolayer interferometry and surface plasmon resonance). ► Interactions between four hydrogenase and/or urease accessory proteins were analyzed. ► Kinetic constants for HypA-UreE and UreE-UreG were determined. ► HypA-UreE interaction is tighter than UreE-UreG. ► A competition between HypA and UreG for UreE was found.