Jeong Jin Hee, Ha Sung Chul
Beamline Department, Pohang Accelerator Laboratory, Pohang University of Science and Technology, 80 Jigok-ro 127 beon-gil, Pohang, Gyeongbuk 37673, Republic of Korea.
Acta Crystallogr F Struct Biol Commun. 2017 Jul 1;73(Pt 7):404-408. doi: 10.1107/S2053230X17008214. Epub 2017 Jun 17.
NisI is a lantibiotic-binding lipoprotein that is specific for nisin. Nisin-producing microorganisms use NisI as an immunity protein for self-protection against nisin. Here, the purification, crystallization and preliminary X-ray diffraction of full-length NisI from Lactobacillus lactis in a lipid-free form (NisI) are reported. Importantly, reductive methylation of the lysine residues in NisI was essential for initial crystallization. Only methylated NisI crystallized. The optimized crystals of methylated NisI were grown in 30-40 mM ammonium sulfate, 0.1 M sodium acetate pH 4.6, 16-18% PEG 4000 at 295 K and diffracted to 1.9 Å resolution. The crystal belonged to space group P222, with unit-cell parameters a = 45.99, b = 76.67, c = 76.39 Å, α = β = γ = 90.0°. Assuming the presence of one molecule in the asymmetric unit, the estimated Matthews coefficient (V) is 2.58 Å Da and the estimated solvent content is 52.3%.
NisI是一种羊毛硫抗生素结合脂蛋白，对乳链菌肽具有特异性。产生乳链菌肽的微生物将NisI用作免疫蛋白，以实现对乳链菌肽的自我保护。在此，报道了来自乳酸乳球菌的无脂形式全长NisI（NisI）的纯化、结晶及初步X射线衍射。重要的是，NisI中赖氨酸残基的还原甲基化对于初始结晶至关重要。只有甲基化的NisI结晶。甲基化NisI的优化晶体在30 - 40 mM硫酸铵、0.1 M乙酸钠pH 4.6、16 - 18%聚乙二醇4000中于295 K生长，并衍射至1.9 Å分辨率。该晶体属于空间群P222，晶胞参数a = 45.99、b = 76.67、c = 76.39 Å，α = β = γ = 90.0°。假设不对称单元中存在一个分子，估计的马修斯系数（V）为2.58 ų Da，估计的溶剂含量为52.3%。
