Each ring type may be particularly suited for different purposes where flexibility or rigidity is advantageous. In terms of a static view of the stability of ring proteins, symmetry itself may not be a determinant of the stability. The smaller population of the 12-mer TRAP compared with the 11- mer is primarily attributed to subtle differences in the inter-subunit interactions. Antson et al. recently found that B. halodurans TRAP exclusively forms a 12-mer ring. The crystal structure of the 12-mer B. halodurans TRAP showed the C-terminal residues with a conformation different from those of the 11-mer TRAP of B. subtilis or B. stearothermophilus, which forms different interactions with the adjacent subunit allowing an increase in the diameter of the ring. However, the present study shows that symmetry significantly influences dynamics, and should be another important factor for not only stability but also biological function of ring proteins, especially for large ring structures like the present case of C11 and C12. The emergence of rapid resistance to antibiotics among major pathogens remains a serious threat to public health. To overcome this challenge, many laboratories pursue drug discovery efforts to identify novel structural classes of antibiotics. However, a limited understanding of the molecular mechanism of action is a critical bottleneck in the development of novel classes of antibacterial agents. Therefore, more detailed studies into the mechanism of microbial death resulting from Ibrutinib antibiotic use and the reason for the drug resistance of pathogens is required. Antibacterial peptides, a cluster of small peptides secreted by most organisms, represent a promising new class of antibiotic drugs. They are known to be active against a wide range of microorganisms including bacteria, protozoa, yeast fungi, viruses, and even tumor cells. These active polypeptides have characteristics of small molecular mass, high efficacy, stability, particular antibacterial mechanism, and little drug resistance. Fusaricidin A was elucidated to be a cyclic depsipeptide containing a unique fatty acid, 15-guanidino-3-hydroxypentadecanoic acid. Fusaricidins B, C, and D are minor components from the culture broth of a bacterial strain Bacillus polymyxa KT-8. Their structures have been elucidated to be cyclic hexadepsipeptide, very similar to that of fusaricidin A. Fusaricidins C and D displayed strong activity against gram-positive bacteria, especially Staphylococcus aureus FDA 209P, S. aureus, and Micrococcus luteus IFO 3333 as did fusaricidin A, whereas fusaricidin B showed weaker activity against those microbes than the fusaricidin C and D mixture. However, fusaricidin, even at 100 mg/mL, showed no activity against all the gram-negative bacteria tested. Despite their promising antimicrobial profile, much remains to be determined regarding the MoA of fusaricidins and the development of microbial resistance to the compounds. In this report, we used genome-wide expression technologies to elucidate bacterial defense mechanisms responsible for fusaricidin resistance; this strategy is increasingly used in the antibiotic research field. As a model organism, we chose B. subtilis 168, a grampositive, spore-forming bacterium that is ubiquitously distributed in soil. The complete genome of B. subtilis 168 was sequenced in 1997 and is reported to encode 4,106 proteins. The availability of this genomic sequence provides a cost-effective opportunity to explore genomic variation between strains. Trancriptomic analysis is a powerful approach to elucidate the inhibitory mechanisms of novel antimicrobial compounds and has been successfully applied to characterize and differentiate antimicrobial actions, often using B. subtilis as a model organism.