Solution Structure of LCI, a Novel Antimicrobial Peptide from Bacillus subtilis

LCI, a 47-residue cationic antimicrobial peptide (AMP) found in Bacillus subtilis, is one of the main effective components that have strong antimicrobial activity against Xanthomonas campestris pv Oryzea and Pseudomonas solanacearum PE1, etc. To provide insight into the activity of the peptide, we used nuclear magnetic resonance spectroscopy to determine the structure of recombinant LCI. The solution structure of LCI has a novel topology, containing a four-strand antiparallel beta-sheet as the dominant secondary structure; It is the first structure of the LCI protein family. Different from any known beta-structure AMPs, LCI contains no disulfide bridge or circular structure, suggesting that LCI is also a novel beta-structure AMP.