Biocathode MCL Curated Metagenome

This file contains the curated metagenome assembled from a combination of eight biological replicates of Illumina short read sequencing data, two closed genomes and one plasmid sequence derived from PacBio RSII sequencing of DNA isolated from two pure cultures, and one closed genome with a plasmid assembled from PacBio metagenomic data.  The genome bins and unbinned contigs matching the three complete genome sequences and two plasmids were removed from the short read metagenome assembly and replaced by the closed sequences.  Raw data, parent metagenome assembly, and isolate sequences are linked through NCBI Bioproject PRJNA244670 at https://www.ncbi.nlm.nih.gov

3‑Substituted Indole Inhibitors Against Francisella tularensis FabI Identified by Structure-Based Virtual Screening

In this study, we describe novel inhibitors against Francisella tularensis SchuS4 FabI identified from structure-based in silico screening with integrated molecular dynamics simulations to account for induced fit of a flexible loop crucial for inhibitor binding. Two 3-substituted indoles, <b>54</b> and <b>57</b>, preferentially bound the NAD⁺ form of the enzyme and inhibited growth of F. tularensis SchuS4 at concentrations near that of their measured <i>K</i>_i. While <b>57</b> was species-specific, <b>54</b> showed a broader spectrum of growth inhibition against F. tularensis, Bacillus anthracis, and Staphylococcus aureus. Binding interaction analysis in conjunction with site-directed mutagenesis revealed key residues and elements that contribute to inhibitor binding and species specificity. Mutation of Arg-96, a poorly conserved residue opposite the loop, was unexpectedly found to enhance inhibitor binding in the R96G and R96M variants. This residue may affect the stability and closure of the flexible loop to enhance inhibitor (or substrate) binding

Oxidase Activity of the Barnacle Adhesive Interface Involves Peroxide-Dependent Catechol Oxidase and Lysyl Oxidase Enzymes

Oxidases are found to play a growing role in providing functional chemistry to marine adhesives for the permanent attachment of macrofouling organisms. Here, we demonstrate active peroxidase and lysyl oxidase enzymes in the adhesive layer of adult Amphibalanus amphitrite barnacles through live staining, proteomic analysis, and competitive enzyme assays on isolated cement. A novel full-length peroxinectin (AaPxt-1) secreted by barnacles is largely responsible for oxidizing phenolic chemistries; AaPxt-1 is driven by native hydrogen peroxide in the adhesive and oxidizes phenolic substrates typically preferred by phenoloxidases (POX) such as laccase and tyrosinase. A major cement protein component AaCP43 is found to contain ketone/aldehyde modifications via 2,4-dinitrophenylhydrazine (DNPH) derivatization, also called Brady’s reagent, of cement proteins and immunoblotting with an anti-DNPH antibody. Our work outlines the landscape of molt-related oxidative pathways exposed to barnacle cement proteins, where ketone- and aldehyde-forming oxidases use peroxide intermediates to modify major cement components such as AaCP43