BackgroundDental caries is a widespread disease that causes dental tissue destruction and leads to local and general complications. Gram-positive bacteria including Streptococcus mutans, Streptococcus sanguinis, and Enterococcus faecalis take part in dental caries formation. Gram-positive bacteria have cell walls that consistof a thick layer of peptidoglycan which maintains the strength and rigidity of the bacteria, as well as bacteria guard from internal osmotic pressure. The biosynthesis of peptidoglycan involves many enzymes, including the Mur family, penicillin binding protein (PBP), and sortases.PurposeThis research has the intention to screen and examine the antibacterial compound of edible plant Kemangi (Ocimum basilicum L.) in terms of how it fights against some oral pathogenic bacteria of E. faecalis ATCC 29212, S. mutans ATCC 25175, and S. sanguinis ATCC 10566.Materials and MethodsThe O. basilicum L. was macerated by several organic solvents to obtain the extracts, before then being purified using several combinations of chromatography methods and the compound was discovered via spectroscopic methods. For the assay against bacteria, the extracts and compounds were tested using agar well diffusion and microdilution assay.ResultsThe isolated compound was identified as β-sitosterol. The compound activity against bacteria was evaluated by in vitro assay against S. sanguinis ATCC 10566 and E. faecalis ATCC 29212 with the MIC and MBC value of 25,000 and 50,000 ppm, respectively. The compound was also tested by in silico study using the molecular docking method. The molecular interaction between β-sitosterol and the protein target showed a lower binding affinity value than the native ligand and other positive controls for each protein. Based on the amino acid residue bound to the ligands, β-sitosterol on MurA and SrtA is not competitive to the positive control, showing potential as a natural antibacterial agent. Meanwhile, on the MurB and PBP, β-sitosterol and positive control do compete with each other.ConclusionThe compound, isolated from O. basilicum L. leaf, was determined as β-sitosterol, which has the molecular formula C29H50O. The antibacterial activity of β-sitosterol by in vitro assay showed weak antibacterial activity, yet exhibited the potential to inhibit the biosynthesis of peptidoglycan and prevent bacteria cell wall formation by inhibiting MurA and SrtA activity via docking simulation.

Bacterial enteric infections resulting in diarrhea, dysentery, or enteric fever constitute a huge public health problem, with more than a billion episodes of disease annually in developing and developed countries. In this study, the deadly agent of hemorrhagic diarrhea and hemolytic uremic syndrome, Escherichia coli O157:H7 was investigated with extensive computational approaches aimed at identifying novel and broad-spectrum antibiotic targets. A systematic in silico workflow consisting of comparative genomics, metabolic pathways analysis, and additional drug prioritizing parameters was used to identify novel drug targets that were essential for the pathogen’s survival but absent in its human host. Comparative genomic analysis of Kyoto Encyclopedia of Genes and Genomes annotated metabolic pathways identified 350 putative target proteins in E. coli O157:H7 which showed no similarity to human proteins. Further bio-informatic approaches including prediction of subcellular localization, calculation of molecular weight, and web-based investigation of 3D structural characteristics greatly aided in filtering the potential drug targets from 350 to 120. Ultimately, 44 non-homologous essential proteins of E. coli O157:H7 were prioritized and proved to have the eligibility to become novel broad-spectrum antibiotic targets and DNA polymerase III alpha (dnaE) was the top-ranked among these targets. Moreover, druggability of each of the identified drug targets was evaluated by the DrugBank database. In addition, 3D structure of the dnaE was modeled and explored further for in silico docking with ligands having potential druggability. Finally, we confirmed that the compounds N-coeleneterazine and N-(1,4-dihydro-5H-tetrazol-5-ylidene)-9-oxo-9H-xanthene-2-sulfon-amide were the most suitable ligands of dnaE and hence proposed as the potential inhibitors of this target protein. The results of this study could facilitate the discovery and release of new and effective drugs against E. coli O157:H7 and other deadly human bacterial pathogens.

Shwachman-Bodian-Diamond syndrome (SBDS) is linked to a mutation in a single gene. The SBDS proinvolved in RNA metabolism and ribosome-associated functions, but SBDS mutation is primarily linked to a defect in polymorphonuclear leukocytes unable to orient correctly in a spatial gradient of chemoattractants. Results of data mining and comparative genomic approaches undertaken in this study suggest that SBDS protein is also linked to tRNA metabolism and translation initiation. Analysis of crosstalk between translation machinery and cytoskeletal dynamics provides new insights into the cellular chemotactic defects caused by SBDS protein malfunction. The proposed functional interactions provide a new approach to exploit potential targets in the treatment and monitoring of this disease.

Artificially synthesized RNA molecules have recently come under study since such molecules have a potential for creating a variety of novel functional molecules. When designing artificial RNA sequences, secondary structure should be taken into account since functions of noncoding RNAs strongly depend on their structure. RNA inverse folding is a methodology for computationally exploring the RNA sequences folding into a user-given target structure. In the present study, we developed a multi-objective genetic algorithm, MODENA (Multi-Objective DEsign of Nucleic Acids), for RNA inverse folding. MODENA explores the approximate set of weak Pareto optimal solutions in the objective function space of 2 objective functions, a structure stability score and structure similarity score. MODENA can simultaneously design multiple different RNA sequences at 1 run, whose lowest free energies range from a very stable value to a higher value near those of natural counterparts. MODENA and previous RNA inverse folding programs were benchmarked with 29 target structures taken from the Rfam database, and we found that MODENA can successfully design 23 RNA sequences folding into the target structures; this result is better than those of the other benchmarked RNA inverse folding programs. The multi-objective genetic algorithm gives a useful framework for a functional biomolecular design. Executable files of MODENA can be obtained at http://rna.eit.hirosaki-u.ac.jp/modena/.

The microtubule network, the major organelle of the eukaryotic cytoskeleton, is involved in cell division and differentiation but also with many other cellular functions. In plants, microtubules seem to be involved in the ordered deposition of cellulose microfibrils by a so far unknown mechanism. Microtubule-associated proteins (MAP) typically contain various domains targeting or binding proteins with different functions to microtubules. Here we have investigated a proposed microtubule-targeting domain, TPX2, first identified in the Kinesin-like protein 2 in Xenopus. A TPX2 containing microtubule binding protein, PttMAP20, has been recently identified in poplar tissues undergoing xylogenesis. Furthermore, the herbicide 2,6-dichlorobenzonitrile (DCB), which is a known inhibitor of cellulose synthesis, was shown to bind specifically to PttMAP20. It is thus possible that PttMAP20 may have a role in coupling cellulose biosynthesis and the microtubular networks in poplar secondary cell walls. In order to get more insight into the occurrence, evolution and potential functions of TPX2-containing proteins we have carried out bioinformatic analysis for all genes so far found to encode TPX2 domains with special reference to poplar PttMAP20 and its putative orthologs in other plants.