In Vitro Biosynthesis and Chemical Identification of UDP-N-acetyl-d-quinovosamine (UDP-d-QuiNAc)

Li, Tiezheng; Simonds, Laurie; Kovrigin, Evgenii L.; Noel, K. Dale

doi:10.1074/jbc.m114.555862

Cited by 13 publications

(12 citation statements)

References 35 publications

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“…We also note that these assignments correspond closely with those recently published for the D-QuiNAc sugar of UDP-D-QuiNAc (Supplementary information, Table S1). 26,27 Hence, the NMR data confirm that the QVMs contain an α1′′, β11′-N-acetylquinovosamine ring in place of the GlcNAc residue for TUNs. Other NMR assignments are essentially identical for the QVMs and TUNs, with the uracil motif confirmed by the characteristic H5 and H-6 signals, the 11-carbon tunicamine dialdose by the two anomeric signals H-1′/C-1′ and H11′/C11′, and the 2,3-unsaturation in the N-acyl chain from the H-2′′′/C-2′′′ and H3′′′/C3′′′ signals (Supplementary information, Table S1).…”

Section: Structural Analysis Of Qvms Using Nmrsupporting

confidence: 57%

Quinovosamycins: new tunicamycin-type antibiotics in which the α, β-1″,11′-linked N-acetylglucosamine residue is replaced by N-acetylquinovosamine

et al. 2016

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Tunicamycins (TUN) are potent inhibitors of polyprenyl phosphate N-acetylhexosamine 1-phosphate transferases (PPHP), including essential eukaryotic GPT enzymes and bacterial HexNAc 1-P translocases. Hence, TUN blocks the formation of eukaryotic N-glycoproteins and the assembly of bacterial call wall polysaccharides. The genetic requirement for TUN production is well-established. Using two genes unique to the TUN pathway (tunB and tunD) as probes we identified four new prospective TUN-producing strains. Chemical analysis showed that one strain, Streptomyces niger NRRL B-3857, produces TUN plus new compounds, named quinovosamycins (QVMs). QVMs are structurally akin to TUN, but uniquely in the 1″,11'-HexNAc sugar head group, which is invariably d-GlcNAc for the known TUN, but is d-QuiNAc for the QVM. Surprisingly, this modification has only a minor effect on either the inhibitory or antimicrobial properties of QVM and TUN. These findings have unexpected consequences for TUN/QVM biosynthesis, and for the specificity of the PPHP enzyme family.

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Section: Structural Analysis Of Qvms Using Nmrsupporting

confidence: 57%

Quinovosamycins: new tunicamycin-type antibiotics in which the α, β-1″,11′-linked N-acetylglucosamine residue is replaced by N-acetylquinovosamine

et al. 2016

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“…IM, inner membrane; OM, outer membrane; PG, peptidoglycan; LPS, lipopolysaccharide. content and changes in the peptidoglycan composition, rendering the bacterium less susceptible to colistin and other AMPs (29)(30)(31)(32). Modifications in the bacterial membrane that reduce or inhibit the AMP-membrane interaction can be achieved indirectly through altered regulators and/or two-component systems.…”

Section: Discussionmentioning

confidence: 99%

Antimicrobial Peptide Exposure Selects for Resistant and Fit Stenotrophomonas maltophilia Mutants That Show Cross-Resistance to Antibiotics

Blanco

Hjort

Martínez

et al. 2020

mSphere

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Antimicrobial peptides (AMPs) are essential components of the innate immune system and have been proposed as promising therapeutic agents against drug-resistant microbes. AMPs possess a rapid bactericidal mode of action and can interact with different targets, but bacteria can also avoid their effect through a variety of resistance mechanisms. Apart from hampering treatment by the AMP itself, or that by other antibiotics in the case of cross-resistance, AMP resistance might also confer cross-resistance to innate human peptides and impair the anti-infective capability of the human host. A better understanding of how resistance to AMPs is acquired and the genetic mechanisms involved is needed before using these compounds as therapeutic agents. Using experimental evolution and whole-genome sequencing, we determined the genetic causes and the effect of acquired de novo resistance to three different AMPs in the opportunistic pathogen Stenotrophomonas maltophilia, a bacterium that is intrinsically resistant to a wide range of antibiotics. Our results show that AMP exposure selects for high-level resistance, generally without any reduction in bacterial fitness, conferred by mutations in different genes encoding enzymes, transporters, transcriptional regulators, and other functions. Cross-resistance to AMPs and to other antibiotic classes not used for selection, as well as collateral sensitivity, was observed for many of the evolved populations. The relative ease by which high-level AMP resistance is acquired, combined with the occurrence of cross-resistance to conventional antibiotics and the maintained bacterial fitness of the analyzed mutants, highlights the need for careful studies of S. maltophilia resistance evolution to clinically valuable AMPs. IMPORTANCE Stenotrophomonas maltophilia is an increasingly relevant multidrug-resistant (MDR) bacterium found, for example, in people with cystic fibrosis and associated with other respiratory infections and underlying pathologies. The infections caused by this nosocomial pathogen are difficult to treat due to the intrinsic resistance of this bacterium against a broad number of antibiotics. Therefore, new treatment options are needed, and considering the growing interest in using AMPs as alternative therapeutic compounds and the restricted number of antibiotics active against S. maltophilia, we addressed the potential for development of AMP resistance, the genetic mechanisms involved, and the physiological effects that acquisition of AMP resistance has on this opportunistic pathogen.

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“…As shown in Table 1B , Preq shares, for example, 33% amino acid sequence identity with functional GDP-4-keto-6-deoxy-D-mannose 4-reductase from Aneurinibacillus thermoaerophilus [ 30 ] and lower sequence homology (24%) with dTDP-glucose 4,6-dehydratase (Rmlb) from Salmonella Enterica serovar Typhimurium [ 31 ]. Also, it shares lower sequence homology (29%) with functional UDP-2-acetamido-2,6-dideoxy-D-xylo-4-hexulose-4-reductase from Rhizobium etili [ 32 ] even though its function, as we will described, is the same with Bacillus protein Preq. Below we provide biochemical evidences of Pdeg (Bc3750) and Preq (Bc3749) proteins for their sequential ability to convert UDP-GlcNAc to UDP-4-keto-6-deoxy-GlcNAc and to UDP-QuiNAc.…”

Section: Resultsmentioning

confidence: 99%

“…While this work was in progress, a study in the gram-negative, Rhizobium etili, discovered for the first time that this bacterium has two enzyme activities [ 32 ] identical to those as described here for the gram-positive bacterium, Bacillus. Both the rhizobium and Bacillus proteins have the same 4,6-dehydratase and 4-reductase activities to make UDP-QuiNAc.…”

Section: Discussionmentioning

confidence: 98%

The Biosynthesis of UDP-d-QuiNAc in Bacillus cereus ATCC 14579

2015

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N-acetylquinovosamine (2-acetamido-2,6-di-deoxy-d-glucose, QuiNAc) is a relatively rare amino sugar residue found in glycans of few pathogenic gram-negative bacteria where it can play a role in infection. However, little is known about QuiNAc-related polysaccharides in gram-positive bacteria. In a routine screen for bacillus glycan grown at defined medium, it was surprising to identify a QuiNAc residue in polysaccharides isolated from this gram-positive bacterium. To gain insight into the biosynthesis of these glycans, we report the identification of an operon in Bacillus cereus ATCC 14579 that contains two genes encoding activities not previously described in gram-positive bacteria. One gene encodes a UDP-N-acetylglucosamine C4,6-dehydratase, (abbreviated Pdeg) that converts UDP-GlcNAc to UDP-4-keto-4,6-d-deoxy-GlcNAc (UDP-2-acetamido-2,6-dideoxy-α-d-xylo-4-hexulose); and the second encodes a UDP-4-reductase (abbr. Preq) that converts UDP-4-keto-4,6-d-deoxy-GlcNAc to UDP-N-acetyl-quinovosamine in the presence of NADPH. Biochemical studies established that the sequential Pdeg and Preq reaction product is UDP-d-QuiNAc as determined by mass spectrometry and one- and two-dimensional NMR experiments. Also, unambiguous evidence for the conversions of the dehydratase product, UDP-α-d-4-keto-4,6-deoxy-GlcNAc, to UDP-α-d-QuiNAc was obtained using real-time 1H-NMR spectroscopy and mass spectrometry. The two genes overlap by 4 nucleotides and similar operon organization and identical gene sequences were also identified in a few other Bacillus species suggesting they may have similar roles in the lifecycle of this class of bacteria important to human health. Our results provide new information about the ability of Bacilli to form UDP-QuiNAc and will provide insight to evaluate their role in the biology of Bacillus.

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In Vitro Biosynthesis and Chemical Identification of UDP-N-acetyl-d-quinovosamine (UDP-d-QuiNAc)

Cited by 13 publications

References 35 publications

Quinovosamycins: new tunicamycin-type antibiotics in which the α, β-1″,11′-linked N-acetylglucosamine residue is replaced by N-acetylquinovosamine

Quinovosamycins: new tunicamycin-type antibiotics in which the α, β-1″,11′-linked N-acetylglucosamine residue is replaced by N-acetylquinovosamine

Antimicrobial Peptide Exposure Selects for Resistant and Fit Stenotrophomonas maltophilia Mutants That Show Cross-Resistance to Antibiotics

The Biosynthesis of UDP-d-QuiNAc in Bacillus cereus ATCC 14579

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