High‐Resolution Structure (1.33 Å) of a HEW Lysozyme Tetragonal Crystal Grown in the APCF Apparatus. Data and Structural Comparison with a Crystal Grown under Microgravity from SpaceHab‐01 Mission
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机译：High‐Resolution Structure (1.33 Å) of a HEW Lysozyme Tetragonal Crystal Grown in the APCF Apparatus. Data and Structural Comparison with a Crystal Grown under Microgravity from SpaceHab‐01 Mission
Crystals of tetragonal hen egg‐white lysozyme were grown using Advanced Protein Crystallization Facility (APCF) apparatus under a microgravity environment (SpaceHab‐01 mission) and ground control conditions. Crystals were grown from NaCl as a crystallizing agent at pH 4.3. The X‐ray diffraction patterns of the best diffracting ground‐ and space‐grown crystals were recorded using synchrotron radiation and an image plate on the W32 beamline at LURE. Both ground‐ and space‐grown crystals showed nearly equivalent maximum resolution of 1.3–1.4 Å. Refinements were carried out with the programX‐PLORwith finalRvalues of 18.45 and 18.27 for structures from ground‐ and space‐ grown crystals, respectively. The two structures are nearly identical with the root‐mean‐square difference on all protein atoms being 0.13 Å. Some residues of the two refined structures show multiple alternative conformations. Two ions were localized into the electron‐density maps of the two structures: one chloride ion at the interface between two symmetry‐related molecules and one sodium ion stabilizing the loop Ser60–Leu75. The sodium ion is surrounded by six ligands which form a bipyrami
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