title: Binding specificity of the lantibiotic-binding immunity protein NukH.
abstract: NukH is a lantibiotic-binding immunity protein that shows strong binding activity against type A(II) lantibiotics. In this study, the binding specificity of NukH was analyzed by using derivatives of nukacin ISK-1, which is a type A(II) lantibiotic produced by Staphylococcus warneri ISK-1. Interactions between cells of Lactococcus lactis transformants expressing nukH and nukacin ISK-1 derivatives were analyzed by using a quantitative peptide-binding assay. Differences in the cell-binding rates of each nukacin ISK-1 derivative suggested that three lysine residues at positions 1 to 3 of nukacin ISK-1 contribute to the effective binding of nukacin ISK-1 to nukH-expressing cells. The binding levels of mutants with lanthionine and dehydrobutyrine substitutions (S11A nukacin(4-27) and T24A nukacin(4-27), respectively) to nukH-expressing cells were considerably lower than those of nukacin(4-27), suggesting that unusual amino acids play a decisive role in NukH recognition. Additionally, it was suggested that T9A nukacin(4-27), a mutant with a 3-methyllanthionine substitution, binds to NukH via an intermolecular disulfide bond after it is weakly recognized by NukH. We succeeded in the detection of specific type A(II) lantibiotics from the culture supernatants of various bacteriocin producers by using the binding specificity of nukH-expressing cells.
authors.affiliation: Laboratory of Microbial Technology, Division of Microbial Science and Technology, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Okuda
authors.forename: Sae
authors.initials: S
authors.lastname: Yanagihara
authors.forename: Kouki
authors.initials: K
authors.lastname: Shioya
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Harada
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Nagao
authors.forename: Yuji
authors.initials: Y
authors.lastname: Aso
authors.forename: Takeshi
authors.initials: T
authors.lastname: Zendo
authors.forename: Jiro
authors.initials: J
authors.lastname: Nakayama
authors.forename: Kenji
authors.initials: K
authors.lastname: Sonomoto
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001430:Bacteriocins / Q000235:genetics / Q000378:metabolism*; D013294:Lactococcus lactis / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D020125:Mutation, Missense; D011485:Protein Binding; D011487:Protein Conformation
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins; D050505:Mutant Proteins; C421186:nukacin ISK-1