Open AccessCharacterization of functional domains of lantibiotic‐binding immunity protein, NukH, from Staphylococcus warneri ISK‐1
Author(s) -
Okuda Kenichi,
Aso Yuji,
Nagao Junichi,
Shioya Kouki,
Kanemasa Youhei,
Nakayama Jiro,
Sonomoto Kenji
Publication year - 2005
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2005.06.039
Subject(s) - lantibiotics , immunity , transmembrane domain , transmembrane protein , biology , innate immune system , function (biology) , amino acid , chemistry , immune system , genetics , bacteria , receptor , bacteriocin
The immunity to a lantibiotic, nukacin ISK‐1, is conferred by NukFEG (ABC transporter) and NukH (lantibiotic‐binding protein) cooperatively. The present study identifies the functional domains of NukH. The topological analysis indicated that NukH possesses two external loops and three transmembrane helices. Deletion of N or C terminus of NukH did not affect the function. Amino acids substitutions in the respective loops abolished the function. Deletion of the third transmembrane helix resulted in loss of immunity but did not affect the binding activity. These findings suggested that the whole structure of NukH, except for N and C termini, is essential for its full immunity function, and that NukH inactivates nukacin ISK‐1 after binding.