2ktn

Publication Abstract from PubMed

A novel synergetic lantibiotic pair, Lchalpha(3249.51 Da) and Lchbeta(3019.36 Da), termed lichenicidin VK21, was isolated from the producer strain Bacillus licheniformis VK21. Chemical and spatial structures of Lchalphaand Lchbeta were determined. Each peptide contains 31 amino acid residues linked by 4 intramolecular thioether bridges and the N-terminal 2-oxobutyryl group. Spatial structures of Lchalpha and Lchbetawere studied by NMR spectroscopy in methanol solution. Lchalpha peptide displays structural homology with mersacidin-like lantibiotics and involves relatively well-structured N- and C-terminal domains connected by a flexible loop stabilized by thioether bridge Ala11-S-Ala21. In contrast, the Lchbetapeptide represents prolonged hydrophobic alpha-helix flanked with more flexible N- and C-terminal domains. A lantibiotic cluster of the Bacillus licheniformis VK21 genome which comprises the structural genes, lchA1 and lchA2, encoding the lantibiotics precursors, as well as the gene of a modifying enzyme lchM1, was amplified and sequenced. The mature peptides, Lchalphaand Lchbetainteract synergistically to possess antibiotic activity against Gram-positive bacteria within a nanomolar concentration range, though the individual peptides were shown to be active at micromolar concentrations. Our results afford molecular insight into mechanism of lichenicidin VK21 action.

Isolation, structure elucidation, and synergistic antibacterial activity of a novel two-component lantibiotic lichenicidin from Bacillus licheniformis VK21.,Shenkarev ZO, Finkina EI, Nurmukhamedova EK, Balandin SV, Mineev KS, Nadezhdin KD, Yakimenko ZA, Tagaev AA, Temirov YV, Arseniev AS, Ovchinnikova TV Biochemistry. 2010 Jun 25. PMID:20578714^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.