Having validated OLIVES against solution protein complexes, we now turn to transmembrane proteins, which are commonly simulated using Martini. Our first test case is the E. coli outer membrane phospholipase A (OMPLA) homodimer (Figure ). OMPLA is a transmembrane β-barrel enzyme that is regulated by reversible dimerization. The interior of the OMPLA barrel is largely polar and out of 257 residues in native contacts in the monomer, 154 are potential hydrogen bonders (SI Figure ). The dimerization of OMPLA activates the enzyme and it has recently been shown by Piller et al. that the dimerization is modulated by membrane asymmetry. Piller et al. show that OMPLA has high activity in a symmetric POPC:POPE bilayer indicating stabilization of the dimer, which makes it an ideal case to test whether the homodimer can be stabilized in Martini 3 simulations without the need for a quaternary network. Furthermore, there have previously been reported problems simulating β-barrel proteins in Martini 2 using elastic networks, and we want to ensure that OLIVES correctly models this protein fold.