A Novel Type of Immunity Protein, NukH, for the Lantibiotic Nukacin ISK-1 Produced byStaphylococcus warneriISK-1

• DOI: 10.1271/bbb.69.1403
• Publication Date: 2005-07-25T10:59:36Z
• Authors: Yuji ASO; Ken-ichi OKUDA; Jun-ichi NAGAO; Youhei KANEMASA; Nguyen THI BICH P...; Hanako KOGA; Kouki SHIOYA; Toshihiro SASHIHARA; Jiro NAKAYAMA; Kenji SONOMOTO
• Keywords: 0301 basic medicine; Staphylococcus; Membrane Proteins; Recombinant Proteins; 3. Good health; Lactococcus lactis; 03 medical and health sciences; Bacterial Proteins; Bacteriocins; Multigene Family; Nisin; Protein Binding

Staphylococcus warneri ISK-1 produces a lantibiotic, nukacin ISK-1. The nukacin ISK-1 gene cluster consists of at least six genes, nukA, -M, -T, -F, -E, and -G, and two open reading frames, ORF1 and ORF7 (designated nukH). Sequence comparisons suggested that NukF, -E, -G, and -H contribute to immunity to nukacin ISK-1. We investigated the immunity levels of recombinant Lactococcus lactis expressing nukFEG and nukH against nukacin ISK-1. The co-expression of nukFEG and nukH resulted in a high degree of immunity. The expression of either nukFEG or nukH conferred partial immunity against nukacin ISK-1. These results suggest that NukH contributes cooperatively to self-protection with NukFEG. The nukacin ISK-1 immunity system might function against another lantibiotic, lacticin 481. Western blot analysis showed that NukH expressed in Staphylococcus carnosus was localized in the membrane. Peptide release/bind assays indicated that the recombinant L. lactis expressing nukH interacted with nukacin ISK-1 and lacticin 481 but not with nisin A. These findings suggest that NukH contributes cooperatively to host immunity as a novel type of lantibiotic-binding immunity protein with NukFEG.