Model of the formation of bis-Mo-MPT and bis-MGD by MobA. It is proposed that two Mo-MPT moieties bind to the proposed MPT and GTP-binding sites on the MobA monomer, thus, enabling first bis-Mo-MPT and then bisMGD synthesis by the addition of two GMP molecules to bis-Mo-MPT. bis-Mo-MPT and bis-MGD are believed to have different binding modes on MobA, resulting in the favourable release of bis-MGD as final product. The structures of MobA were modeled using the coordinates from the Protein Data Bank (1FRW) and the figure was adapted from the one shown in [25].