Evidence of an intracellular interaction between the Escherichia coli enzymes EntC and EntB and identification of a potential electrostatic channeling surface.

Siderophores are high-affinity small-molecule chelators employed by bacteria to acquire iron from the extracellular environment. The Gram-negative bacterium Escherichia coli synthesizes and secretes enterobactin, a tris-catechol siderophore. Enterobactin is synthesized by six cytoplasmic enzyme activities: EntC, EntB (isochorismatase (IC) domain), EntA, EntE, EntB (aryl carrier protein (ArCP) domain), and EntF.

Kinetic Characterization of SARS-CoV-2 nsp13 ATPase Activity and Discovery of Small-Molecule Inhibitors.

SARS-CoV-2 non-structural protein 13 (nsp13) is a highly conserved helicase and RNA 5'-triphosphatase. It uses the energy derived from the hydrolysis of nucleoside triphosphates for directional movement along the nucleic acids and promotes the unwinding of double-stranded nucleic acids. Nsp13 is essential for replication and propagation of all human and non-human coronaviruses.

The Structure-Based Design of SARS-CoV-2 nsp14 Methyltransferase Ligands Yields Nanomolar Inhibitors.

In this study, we have focused on the structure-based design of the inhibitors of one of the two SARS-CoV-2 methyltransferases (MTases), nsp14. This MTase catalyzes the transfer of the methyl group from -adenosyl-l-methionine (SAM) to cap the guanosine triphosphate moiety of the newly synthesized viral RNA, yielding the methylated capped RNA and -adenosyl-l-homocysteine (SAH). As the crystal structure of SARS-CoV-2 nsp14 is unknown, we have taken advantage of its high homology to SARS-CoV nsp14 and prepared its homology model, which has allowed us to identify novel SAH derivatives modified at the adenine nucleobase as inhibitors of this important viral target.

A novel set of vectors for Fur-controlled protein expression under iron deprivation in Escherichia coli.

Background: In the presence of sufficient iron, the Escherichia coli protein Fur (Ferric Uptake Regulator) represses genes controlled by the Fur box, a consensus sequence near or within promoters of target genes. De-repression of Fur-controlled genes occurs upon iron deprivation. In the E.

Intracellular co-localization of the Escherichia coli enterobactin biosynthetic enzymes EntA, EntB, and EntE.

Bacteria utilize small-molecule iron chelators called siderophores to support growth in low-iron environments. The Escherichia coli catecholate siderophore enterobactin is synthesized in the cytoplasm upon iron starvation. Seven enzymes are required for enterobactin biosynthesis: EntA-F, H.

Subunit orientation in the Escherichia coli enterobactin biosynthetic EntA-EntE complex revealed by a two-hybrid approach.

The siderophore enterobactin is synthesized by the enzymes EntA-F and EntH in the Escherichia coli cytoplasm. We previously reported in vitro evidence of an interaction between tetrameric EntA and monomeric EntE. Here we used bacterial adenylate cyclase two-hybrid (BACTH) assays to demonstrate that the E.

An anillin-Ect2 complex stabilizes central spindle microtubules at the cortex during cytokinesis.

Cytokinesis occurs due to the RhoA-dependent ingression of an actomyosin ring. During anaphase, the Rho GEF (guanine nucleotide exchange factor) Ect2 is recruited to the central spindle via its interaction with MgcRacGAP/Cyk-4, and activates RhoA in the central plane of the cell. Ect2 also localizes to the cortex, where it has access to RhoA.