Spezifität, Struktur und Funktion der Lantibiotika-Immunitätsproteine SpaI und NisI
Zusammenfassung der Projektergebnisse
The project established that LanI proteins contain a novel class of protein fold that was found in the SpaI as well as in two copies in the N- and C-terminal domains of NisI. This fold apparently is able to evolve into functionally distinct roles as demonstrated in NisI where the N-terminal domain mediates membrane binding whereas the C-terminal domain binds directly and specific to the lantibiotic. We also obtained insights into the complex interdomain dynamics of NisI and established its mode of interaction with membranes and nisin. A direct interation of subtilin with its immunity SpaI could be demonstrated with LILBID mass spectrometry. For the first time a particular role of immunity proteins SpaI and NisI in preventing pore-formation could be shown: Furthermore, it turned out that the N-terminal and C-terminal parts of linear lantibiotics are of different physiological importance. Whereas the N-terminal part in needed for autoinduction and the interaction with lipid II, the C-terminal part is important for pore-formation in complex with lipid II and for immunity provided by SpaI and NisI. Not all aims of the original proposal could be reached in the course of our work. In particular, we were unable to solve the structure of a LanI-lantibiotic complex that would provide insights into their interactions at atomic resolution. However, since the complex of NisI and nisin was in intermediate exchange on the NMR time scale and did not crystallize while experiments with subtilin variants and SpaI were plagued by solubility problems for the lantibiotic such a structure will have to await the identification of other lantibiotic-LanI complexes with different properties. Experiments to this end are currently ongoing in our laboratories.
Projektbezogene Publikationen (Auswahl)
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Autoinduction specificities of the lantibiotics subtilin and nisin. Appl. Environ. Microbiol. 2015, 81:7914-7923
T. Spieß, S. M. Korn, P. Kötter, K.-D. Entian
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NMR resonance assignments of the lantibiotic immunity protein NisI from Lactococcus lactis. Biomol. NMR Assign. 2015, 9:293-297
C. Hacker, N. A. Christ, E. Duchardt-Ferner, S. Korn, L. Berninger, P. Kötter, K.-D. Entian, J. Wöhnert
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The solution structure of the lantibiotic immunity protein NisI and its interactions with nisin. J. Biol. Chem. 2015, 290: 28869-28886
C. Hacker, N. A. Christ, E. Duchardt-Ferner, S. Korn, C. Goebl, L. Berninger, S. Düsterhus, U. A. Hellmich, P. Koetter, T. Madl, K.-D. Entian, J. Wöhnert
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Specificity of subtilinmediated activation of histidine kinase SpaK. Appl. Environ. Microbiol. 2017, Jul 14
C. Geiger, T. Spieß, S. M. Korn, P. Kötter, K.-D. Entian
