Escherichia coli monothiol glutaredoxin GrxD replenishes Fe-S clusters to the essential ErpA A-type carrier under low iron stress.

Iron-sulfur (Fe-S) clusters are required for essential biological pathways, including respiration and isoprenoid biosynthesis. Complex Fe-S cluster biogenesis systems have evolved to maintain an adequate supply of this critical protein cofactor. In Escherichia coli, two Fe-S biosynthetic systems, the "housekeeping" Isc and "stress responsive" Suf pathways, interface with a network of cluster trafficking proteins, such as ErpA, IscA, SufA, and NfuA.

Facial amphiphilic naphthoic acid-derived antimicrobial polymers against multi-drug resistant gram-negative bacteria and biofilms.

Inspired by the facial amphiphilic nature and antimicrobial efficacy of many antimicrobial peptides, this work reported facial amphiphilic bicyclic naphthoic acid derivatives with different ratios of charges to rings that were installed onto side chains of poly(glycidyl methacrylate). Six quaternary ammonium-charged (QAC) polymers were prepared to investigate the structure-activity relationship. These QAC polymers displayed potent antibacterial activity against various multi-drug resistant (MDR) gram-negative pathogens such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii.

Ni-NTA Affinity Chromatography to Characterize Protein-Protein Interactions During Fe-S Cluster Biogenesis.

Affinity chromatography can be repurposed to provide useful information about the specific partner protein(s) to which a protein of interest may bind as well as the relative binding affinity of that partner protein for the protein of interest. Here, we provide a protocol for an Ni-NTA affinity chromatography assay that may be utilized to uncover insightful information about the nature of protein-protein interactions during iron-sulfur (Fe-S) cluster biogenesis reactions.

Fe-S cluster biogenesis by the bacterial Suf pathway.

Biogenesis of iron-sulfur (FeS) clusters in an essential process in living organisms due to the critical role of FeS cluster proteins in myriad cell functions. During biogenesis of FeS clusters, multi-protein complexes are used to drive the mobilization and protection of reactive sulfur and iron intermediates, regulate assembly of various FeS clusters on an ATPase-dependent, multi-protein scaffold, and target nascent clusters to their downstream protein targets. The evolutionarily ancient sulfur formation (Suf) pathway for FeS cluster assembly is found in bacteria and archaea.

Direct observation of intermediates in the SufS cysteine desulfurase reaction reveals functional roles of conserved active-site residues.

Iron-sulfur (Fe-S) clusters are necessary for the proper functioning of numerous metalloproteins. Fe-S cluster (Isc) and sulfur utilization factor (Suf) pathways are the key biosynthetic routes responsible for generating these Fe-S cluster prosthetic groups in Although Isc dominates under normal conditions, Suf takes over during periods of iron depletion and oxidative stress. Sulfur acquisition via these systems relies on the ability to remove sulfur from free cysteine using a cysteine desulfurase mechanism.