TELSAM polymers accelerate crystallization of fused target proteins by stabilizing minimal crystal contacts and in the absence of direct inter-TELSAM contacts

Abstract

We extend investigation into the usefulness of genetic fusion to TELSAM polymers as an effective protein crystallization strategy. We tested various numbers of the target protein fused per turn of the TELSAM helical polymer and various TELSAM-target connection strategies. We provide definitive evidence that: 1. A TELSAM-target protein fusion can crystallize more rapidly than the same target protein alone, 2. TELSAM-target protein fusions can form well-ordered, diffracting crystals using either flexible or rigid TELSAM-target linkers, 3. Well-ordered crystals can be obtained when either 2 or 6 copies of the target protein are presented per turn of the TELSAM helical polymer, 4. The TELSAM polymers themselves need not directly contact one another in the crystal lattice, and 5. Fusion to TELSAM polymer confers immense avidity to stabilize exquisitely weak inter-target protein crystal contacts. We report features of TELSAM-target protein crystals and outline future work needed to define the requirements for reliably obtaining optimal crystals of TELSAM-target protein fusions.