Full-length nisin immunity protein NisI from Lactococcus lactis in a lipid-free form: crystallization and X-ray analysis.

ABSTRACT: 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 (NisI22-C) are reported. Importantly, reductive methylation of the lysine residues in NisI22-C was essential for initial crystallization. Only methylated NisI22-C crystallized. The optimized crystals of methylated NisI22-C 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 P212121, with unit-cell parameters a = 45.99, b = 76.67, c = 76.39?Å, ? = ? = ? = 90.0°. Assuming the presence of one molecule in the asymmetric unit, the estimated Matthews coefficient (VM) is 2.58?Å3?Da-1 and the estimated solvent content is 52.3%.

SUBMITTER: Jeong JH 

PROVIDER: S-EPMC5505245 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature