Antibacterial Nucleoside-Analog Inhibitor of Bacterial RNA Polymerase (original) (raw)

Antibacterial nucleoside-analog inhibitor of bacterial RNA polymerase: pseudouridimycin

2017

There is an urgent need for new antibacterial drugs effective against bacterial pathogens resistant to current drugs. Nucleoside-analog inhibitors (NAIs) of viral nucleotide polymerases have had transformative impact in treatment of HIV and HCV. NAIs of bacterial RNA polymerase (RNAP) potentially could have major impact on treatment of bacterial infection, particularly because functional constraints on substitution of RNAP nucleoside triphosphate (NTP) binding sites could limit resistance emergence. Here we report the discovery, from microbial extract screening, of an NAI that inhibits bacterial RNAP and exhibits antibacterial activity against a broad spectrum of drug-sensitive and drug-resistant bacterial pathogens: pseudouridimycin (PUM). PUM is a novel microbial natural product consisting of a formamidinylated, N-hydroxylated Gly-Gln dipeptide conjugated to 6'-amino-pseudouridine. PUM potently and selectively inhibits bacterial RNAP in vitro, potently and selectively inhibits...

Faculty of 1000 evaluation for Antibacterial Nucleoside-Analog Inhibitor of Bacterial RNA Polymerase

F1000 - Post-publication peer review of the biomedical literature

Drug-resistant bacterial pathogens pose an urgent public-health crisis. Here, we report the discovery, from microbial-extract screening, of a nucleoside-analog inhibitor that inhibits bacterial RNA polymerase (RNAP) and exhibits antibacterial activity against drug-resistant bacterial pathogens: pseudouridimycin (PUM). PUM is a natural product comprising a formamidinylated, N-hydroxylated Gly-Gln dipeptide conjugated to 6′-amino-pseudouridine. PUM potently and selectively inhibits bacterial RNAP in vitro, inhibits bacterial growth in culture, and clears infection in a mouse model of Streptococcus pyogenes peritonitis. PUM inhibits RNAP through a binding site on RNAP (the NTP addition site) and mechanism (competition with UTP for occupancy of the NTP addition site) that differ from those of the RNAP inhibitor and current antibacterial drug rifampin (Rif). PUM exhibits additive antibacterial activity when coadministered with Rif, exhibits no cross-resistance with Rif, and exhibits a spontaneous resistance

Discovery, properties, and biosynthesis of pseudouridimycin, an antibacterial nucleoside-analog inhibitor of bacterial RNA polymerase

Journal of Industrial Microbiology and Biotechnology, 2018

Pseudouridimycin (PUM) is a novel pseudouridine-containing peptidyl-nucleoside antibiotic that inhibits bacterial RNA polymerase (RNAP) through a binding site and mechanism different from those of clinically approved RNAP inhibitors of the rifamycin and lipiarmycin (fidaxomicin) classes. PUM was discovered by screening microbial fermentation extracts for RNAP inhibitors. In this review, we describe the discovery and characterization of PUM. We also describe the RNAP-inhibitory and antibacterial properties of PUM. Finally, we review available information on the gene cluster and pathway for PUM biosynthesis and on the potential for discovering additional novel pseudouridine-containing nucleoside antibiotics by searching bacterial genome and metagenome sequences for sequences similar to pumJ, the pseudouridine-synthase gene of the PUM biosynthesis gene cluster.

A new class of small molecule RNA polymerase inhibitors with activity against Rifampicin-resistant Staphylococcus aureus1

Bioorganic & Medicinal Chemistry, 2006

The RNA polymerase holoenzyme is a proven target for antibacterial agents. A high-throughput screening program based on this enzyme from Staphylococcus aureus had previously identified a 2-ureidothiophene-3-carboxylate as a low micromolar inhibitor. An investigation of the relationships between the structures of this class of compounds and their inhibitory-and antibacterial activities is described here, leading to a set of potent RNA polymerase inhibitors with antibacterial activity. Characterization of this bioactivity, including studies of the mechanism of action, is provided, highlighting the power of the reverse chemical genetics approach in providing tools to inhibit the bacterial RNA polymerase.

Novel inhibitors of Staphylococcus aureus RnpA that synergize with mupirocin

Bioorganic & Medicinal Chemistry Letters, 2018

We recently discovered RnpA as a promising new drug discovery target for methicillin-resistant S. aureus (MRSA). RnpA is an essential protein that is thought to perform two required cellular processes. As part of the RNA degrasome Rnpa mediates RNA degradation. In combination with rnpB it forms RNase P haloenzymes which are required for tRNA maturation. A high throughput screen identified RNPA2000 as an inhibitor of both RnpA-associated activities that displayed antibacterial activity against clinically relevant strains of S. aureus, including MRSA. Structure-activity studies aimed at improving potency and replacing the potentially metabotoxic furan moiety led to the identification of a number of more potent analogs. Many of these new analogs possessed overt cellular toxicity that precluded their use as antibiotics but two derivatives, including compound 5o, displayed an impressive synergy with mupirocin, an antibiotic used for decolonizing MSRA whose effectiveness has recently been jeopardized by bacterial resistance. Based on our results, compounds like 5o may ultimately find use in resensitizing mupirocin-resistant bacteria to mupirocin.

Characterization of C-nucleoside Antimicrobials from Streptomyces albus DSM 40763: Strepturidin is Pseudouridimycin

Scientific Reports, 2019

Pseudouridimycin (PUM), a selective inhibitor of bacterial RNA polymerase has been previously detected in microbial-extracts of two strains of Streptomyces species (strain ID38640 and ID38673). Here, we isolated PUM and its deoxygenated analogue desoxy-pseudouridimycin (dPUM) from Streptomyces albus DSM 40763, previously reported to produce the metabolite strepturidin (STU). The isolated compounds were characterized by HRMS and spectroscopic techniques and they selectively inhibited transcription by bacterial RNA polymerase as previously reported for PUM. In contrast, STU could not be detected in the cultures of S. albus DSM 40763. As the reported characteristics reported for STU are almost identical with that of PUM, the existence of STU was questioned. We further sequenced the genome of S. albus DSM 40763 and identified a gene cluster that contains orthologs of all PUM biosynthesis enzymes but lacks the enzymes that would conceivably allow biosynthesis of STU as an additional prod...

Mechanisms of antibiotics inhibiting bacterial RNA polymerase

Biochemical Society Transactions, 2019

Transcription, the first phase of gene expression, is performed by the multi-subunit RNA polymerase (RNAP). Bacterial RNAP is a validated target for clinical antibiotics. Many natural and synthetic compounds are now known to target RNAP, inhibiting various stages of the transcription cycle. However, very few RNAP inhibitors are used clinically. A detailed knowledge of inhibitors and their mechanisms of action (MOA) is vital for the future development of efficacious antibiotics. Moreover, inhibitors of RNAP are often useful tools with which to dissect RNAP function. Here, we review the MOA of antimicrobial transcription inhibitors.

Affinity Selection-Mass Spectrometry Identifies a Novel Antibacterial RNA Polymerase Inhibitor

ACS chemical biology, 2017

The growing prevalence of drug resistant bacteria is a significant global threat to human health. The antibacterial drug rifampin, which functions by inhibiting bacterial RNA polymerase (RNAP), is an important part of the antibacterial armamentarium. Here, in order to identify novel inhibitors of bacterial RNAP, we used affinity-selection mass spectrometry to screen a chemical library for compounds that bind to Escherichia coli RNAP. We identified a novel small molecule, MRL-436, that binds to RNAP, inhibits RNAP, and exhibits antibacterial activity. MRL-436 binds to RNAP through a binding site that differs from the rifampin binding site, inhibits rifampin-resistant RNAP derivatives, and exhibits antibacterial activity against rifampin-resistant strains. Isolation of mutants resistant to the antibacterial activity of MRL-436 yields a missense mutation in codon 622 of the rpoC gene encoding the RNAP β' subunit or a null mutation in the rpoZ gene encoding the RNAP ω subunit, confi...

RNA as A Potent Target for Antibacterial Drug Discovery

Biomedical Journal of Scientific & Technical Research

The development of novel antibiotics is becoming a real emergency due to the growing number of multidrug-resistant pathogenic bacteria. This is also a global problem due to mass production and application of various antibiotics both in human and veterinary medicine. Therefore, we need not only to create novel antibiotics but also to speed up the development pipeline. This may be achieved by using novel targets for antibacterial drug discovery. In this review, we focus our attention on several different types of RNA molecules that have been used as antibacterial drug targets. The RNA is the most ambiguous biopolymer in the cell, which carries many different functions. For instance, tRNAs, rRNAs, and mRNAs are essential for gene expression both in the pro-and eukaryotes. However, all these types of RNAs have sequences and something 3D structures that are specific for bacteria only and can be used to shut down essential biochemical processes in bacteria only. All these features make RNA very potent target for antibacterial drug development.