RBX1-15

• Submission order: 15
• Score rank: 15
• Format: Mini-protein
• Primary state: 8Q7R functional state
• Design method: BindCraft backbone plus ProteinMPNN redesign
• Description: This functional-state backup remains useful because it explores a second E2-facing packing arrangement, which matters if the top functional-state geometry proves too narrow experimentally. The working model targets a functional RBX1 conformation related to the E2-facing interface in the 8Q7R functional state, and follow-up refolds recovered compatible placements in the 2LGV display-state conformation, the 3RTR transfer-related conformation, the 4F52 main-face conformation, and the 8PQL functional-state conformation. The key numerical signals are a modeled contact patch built around 3 residues on the binder side, a patch that currently touches 1 residue on RBX1, localized RBX1 surface coverage of 0.167, solid interface confidence at 0.765, strong developability at 0.934, and a composite ranking score of 5.4644. Novelty support is acceptable: the UniRef50 30-aa sliding-window screen is clear; no strong competing interaction is flagged in the off-target screen; the main caution is that the modeled interface remains relatively narrow, even though the fold-level signal is encouraging; the full project rationale and design workflow are documented at https://github.com/tuna010101/RBX1-Binder-Design-Portfolio