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crystallization communications
The N-terminal cytoplasmic domain of the Na+-coupled HCO
cotransporter NBCe1-A (NtNBCe1) has been linked with proximal renal tubular acidosis. In a previous purification study of recombinant NtNBCe1, crystal growth at a suboptimal protein concentration (<1 mg ml−1) yielded small single diamond-shaped crystals that diffracted poorly. In the present study, by increasing the protein concentration 50-fold, the crystal size was doubled and robustness was also improved. Crystal annealing made the crystals suitable for X-ray diffraction. The crystals either belong to space group P3121 or P31 with pseudo P3121 symmetry, with unit-cell parameters a = 51.7, b = 51.7, c = 200.6 Å, α = β = 90, γ = 120°, and diffract X-rays to 3.0 Å resolution. The calculated Matthews number is 1.9 Å3 Da−1, with two monomers of molecular weight ∼83 kDa in the asymmetric unit. The molecular- replacement packing solution shows that the molecules form dimers by a domain-swapping mechanism.
cotransporter NBCe1-A (NtNBCe1) has been linked with proximal renal tubular acidosis. In a previous purification study of recombinant NtNBCe1, crystal growth at a suboptimal protein concentration (<1 mg ml−1) yielded small single diamond-shaped crystals that diffracted poorly. In the present study, by increasing the protein concentration 50-fold, the crystal size was doubled and robustness was also improved. Crystal annealing made the crystals suitable for X-ray diffraction. The crystals either belong to space group P3121 or P31 with pseudo P3121 symmetry, with unit-cell parameters a = 51.7, b = 51.7, c = 200.6 Å, α = β = 90, γ = 120°, and diffract X-rays to 3.0 Å resolution. The calculated Matthews number is 1.9 Å3 Da−1, with two monomers of molecular weight ∼83 kDa in the asymmetric unit. The molecular- replacement packing solution shows that the molecules form dimers by a domain-swapping mechanism.
