TipA, a Bdellovibrio bacteriovorus BPI-like double-TULIP is opened by its adapter protein, TipB
This study reveals that the predatory bacterium *Bdellovibrio bacteriovorus* utilizes a unique double-TULIP protein, TipA, which forms a lipid-sequestering homodimer that is structurally opened by its adapter protein TipB, representing the first example of an adaptor-mediated conformational change in TULIPs.