Bacterial conjugation is a contact-dependent form of horizontal gene transfer where DNA is transferred in a unidirectional manner from a donor to recipient bacterium. It is also a key driver of the spread of antimicrobial resistance plasmids within clinically important pathogens. The intimate attachment of cells within a conjugating pair is crucial for efficient DNA transfer. However, the mechanism underlying the formation of tight mating junctions, which occurs through a process termed mating pair stabilization (MPS), is unclear. This work describes how variants of the plasmid-encoded outer membrane protein TraN interact with different receptors on recipient cells to mediate MPS. Using a reporter plasmid generated from the Klebsiella pneumoniae carbapenem resistance plasmid pKpQIL, mutations in the major outer membrane porin OmpK36 were found to reduce plasmid uptake in recipients. Meanwhile, substitution of traN on this plasmid with traN from two related plasmids, the Shigella flexneri resistance plasmid, R100-1 and the prototypical F plasmid, revealed that these TraN variants mediate dependency on recipient OmpW and OmpA respectively instead. Structural analysis showed that TraN from pKpQIL forms a complex with OmpK36 via the insertion of a β-hairpin structure into one of the subunits of the trimeric porin. Combining bioinformatic analysis and structural predictions using AlphaFold, four additional TraN variants were identified. All seven TraN variants could be classified into four groups based on their structural similarity and associated receptors: TraNα (OmpW), TraNβ (OmpK36), TraNγ (OmpA) and TraNδ (OmpF). Species specificity was also observed during MPS as not all homologues of a receptor are recognized by each TraN. This specificity was reflected in the real-world host distribution of conjugative IncF plasmids suggesting that MPS plays an influential role in shaping the host range of these plasmids. These findings provide a precedent for developing strategies that target MPS to mitigate resistance gene dissemination.