scholarly journals Plasticity and Evolution of Aeruginosin Biosynthesis in Cyanobacteria

2009 ◽  
Vol 75 (7) ◽  
pp. 2017-2026 ◽  
Author(s):  
Keishi Ishida ◽  
Martin Welker ◽  
Guntram Christiansen ◽  
Sabrina Cadel-Six ◽  
Christiane Bouchier ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Common Ancestor ◽  
Structural Diversity ◽  
Gene Clusters ◽  
Adenylation Domain ◽  
Peptide Synthetase ◽  
Structural Peculiarities ◽  
Tailoring Enzymes ◽  
The Individual ◽  
Insight Into

ABSTRACT Aeruginosins are bioactive oligopeptides that are produced in high structural diversity by strains of the bloom-forming cyanobacterial genera Microcystis and Planktothrix. A hallmark of aeruginosins is the unusual Choi moiety central to the tetrapeptides, while other positions are occupied by variable moieties in individual congeners. Here we report on three aeruginosin synthetase gene clusters (aer) of Microcystis aeruginosa (strains PCC 7806, NIES-98, and NIES-843). The analysis and comparison the aer gene clusters provide the first insight into the molecular basis of biosynthetic and structural plasticity in aeruginosin pathways. Major parts of the aer gene clusters are highly similar in all strains, particularly the genes coding for the first three nonribosomal peptide synthetase (NRPS) modules except for the region coding for the second adenylation domain. However, the gene clusters differ largely in genes coding for tailoring enzymes such as halogenases and sulfotransferases, reflecting structural peculiarities in aeruginosin congeners produced by the individual strains. Significant deviations were further observed in the C-terminal NRPS modules, suggesting two distinct release mechanisms. The architecture of the gene clusters is in agreement with the particular aeruginosin variants that are produced by individual strains, the structures of two of which (aeruginosins 686 A and 686 B) were elucidated. The aer gene clusters of Microcystis and Planktothrix are proposed to originate from a common ancestor and to have evolved to their present-day diversity largely through horizontal gene transfer and recombination events.

scholarly journals Genomics-Driven Activation of Silent Biosynthetic Gene Clusters in Burkholderia gladioli by Screening Recombineering System

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 700
Author(s):  
Hanna Chen ◽  
Tao Sun ◽  
Xianping Bai ◽  
Jie Yang ◽  
Fu Yan ◽  
...  
Keyword(s):  
Genetic Manipulation ◽  
Structural Diversity ◽  
Gene Clusters ◽  
Unnatural Amino Acid ◽  
Biosynthetic Gene ◽  
Assembly Lines ◽  
Biosynthetic Gene Clusters ◽  
Genome Modification ◽  
Burkholderia Gladioli ◽  
Peptide Synthetase

The Burkholderia genus possesses ecological and metabolic diversities. A large number of silent biosynthetic gene clusters (BGCs) in the Burkholderia genome remain uncharacterized and represent a promising resource for new natural product discovery. However, exploitation of the metabolomic potential of Burkholderia is limited by the absence of efficient genetic manipulation tools. Here, we screened a bacteriophage recombinase system Redγ-BAS, which was functional for genome modification in the plant pathogen Burkholderia gladioli ATCC 10248. By using this recombineering tool, the constitutive promoters were precisely inserted in the genome, leading to activation of two silent nonribosomal peptide synthetase gene clusters (bgdd and hgdd) and production of corresponding new classes of lipopeptides, burriogladiodins A–H (1–8) and haereogladiodins A–B (9–10). Structure elucidation revealed an unnatural amino acid Z- dehydrobutyrine (Dhb) in 1–8 and an E-Dhb in 9–10. Notably, compounds 2–4 and 9 feature an unusual threonine tag that is longer than the predicted collinearity assembly lines. The structural diversity of burriogladiodins was derived from the relaxed substrate specificity of the fifth adenylation domain as well as chain termination conducted by water or threonine. The recombinase-mediating genome editing system is not only applicable in B. gladioli, but also possesses great potential for mining meaningful silent gene clusters from other Burkholderia species.

scholarly journals Substrate recognition by nonribosomal peptide synthetase multi-enzymes

Microbiology ◽  
2004 ◽  
Vol 150 (6) ◽  
pp. 1629-1636 ◽  
Author(s):  
Sylvie Lautru ◽  
Gregory L. Challis
Keyword(s):  
Molecular Basis ◽  
Substrate Selectivity ◽  
Substrate Selection ◽  
Nonribosomal Peptide ◽  
Peptide Synthetases ◽  
Peptide Synthetase ◽  
Commercially Important ◽  
Potential Impact ◽  
Bacteria And Fungi ◽  
The Individual

Nonribosomal peptide synthetases (NRPSs) are giant multi-domain enzymes that catalyse the biosynthesis of many commercially important peptides produced by bacteria and fungi. Several studies over the last decade have shown that many of the individual domains within NRPSs exhibit significant substrate selectivity, which impacts on our ability to engineer NRPSs to produce new bioactive microbial peptides. Adenylation domains appear to be the primary determinants of substrate selectivity in NRPSs. Much progress has been made towards an empirical understanding of substrate selection by these domains over the last 5 years, but the molecular basis of substrate selectivity in these domains is not yet well understood. Perhaps surprisingly, condensation domains have also been reported to exhibit moderate to high substrate selectivity, although the generality of this observation and its potential impact on engineered biosynthesis experiments has yet to be fully elucidated. The situation is less clear for the thioesterase domains, which seem in certain cases to be dedicated to the hydrolysis/cyclization of their natural substrate, whereas in other cases they are largely permissive.

scholarly journals A non-canonical peptide synthetase adenylates 3-methyl-2-oxovaleric acid for auriculamide biosynthesis

2016 ◽  
Vol 12 ◽  
pp. 2766-2770 ◽  
Author(s):  
Daniel Braga ◽  
Dirk Hoffmeister ◽  
Markus Nett
Keyword(s):  
Structural Variation ◽  
Genetic Locus ◽  
Functional Characterization ◽  
Structural Diversity ◽  
Building Blocks ◽  
Adenylation Domain ◽  
Proteinogenic Amino Acid ◽  
Keto Acids ◽  
Peptide Synthetase

Auriculamide is the first natural product known from the predatory bacteriumHerpetosiphon aurantiacus.It is composed of three unusual building blocks, including the non-proteinogenic amino acid 3-chloro-L-tyrosine, the α-hydroxy acid L-isoleucic acid, and a methylmalonyl-CoA-derived ethane unit. A candidate genetic locus for auriculamide biosynthesis was identified and encodes four enzymes. Among them, the non-canonical 199 kDa four-domain nonribosomal peptide synthetase, AulA, is extraordinary in that it features two consecutive adenylation domains. Here, we describe the functional characterization of the recombinantly produced AulA. The observed activation of 3-methyl-2-oxovaleric acid by the enzyme supports the hypothesis that it participates in the biosynthesis of auriculamide. An artificially truncated version of AulA that lacks the first adenylation domain activated this substrate like the full-length enzyme which shows that the first adenylation domain is dispensable. Additionally, we provide evidence that the enzyme tolerates structural variation of the substrate. α-Carbon substituents significantly affected the substrate turnover. While all tested aliphatic α-keto acids were accepted by the enzyme and minor differences in chain size and branches did not interfere with the enzymatic activity, molecules with methylene α-carbons led to low turnover. Such enzymatic plasticity is an important attribute to help in the perpetual search for novel molecules and to access a greater structural diversity by mutasynthesis.

Phylogeny of actin and tubulin gene homologs in diverse eukaryotic species

2019 ◽  
Vol 79 (01S) ◽  
Author(s):  
Pawan Kumar Jayaswal ◽  
Asheesh Shanker ◽  
Nagendra Kumar Singh
Keyword(s):  
Evolutionary Relationship ◽  
Genomic Data ◽  
Gene Clusters ◽  
Species Trees ◽  
Model Species ◽  
Tubulin Gene ◽  
Tubulin Genes ◽  
Eukaryotic Species ◽  
Relationship Of ◽  
Insight Into

Actin and tubulin are cytoskeleton proteins, which are important components of the celland are conserved across species. Despite their crucial significance in cell motility and cell division the distribution and phylogeny of actin and tubulin genes across taxa is poorly understood. Here we used publicly available genomic data of 49 model species of plants, animals, fungi and Protista for further understanding the distribution of these genes among diverse eukaryotic species using rice as reference. The highest numbers of rice actin and tubulin gene homologs were present in plants followed by animals, fungi and Protista species, whereas ten actin and nine tubulin genes were conserved in all 49 species. Phylogenetic analysis of 19 actin and 18 tubulin genes clustered them into four major groups each. One each of the actin and tubulin gene clusters was conserved across eukaryotic species. Species trees based on the conserved actin and tubulin genes showed evolutionary relationship of 49 different taxa clustered into plants, animals, fungi and Protista. This study provides a phylogenetic insight into the evolution of actin and tubulin genes in diverse eukaryotic species.

What Can Economists Contribute to the Common Good Tradition?

2017 ◽  
Author(s):  
Andrew M. Yuengert
Keyword(s):  
Common Good ◽  
Common Pool Resources ◽  
Economic Approach ◽  
Public And Private ◽  
Private Provision ◽  
The Public ◽  
The Common Good ◽  
The Common ◽  
The Individual ◽  
Insight Into

Although most economists are skeptical of or puzzled by the Catholic concept of the common good, a rejection of the economic approach as inimical to the common good would be hasty and counterproductive. Economic analysis can enrich the common good tradition in four ways. First, economics embodies a deep respect for economic agency and for the effects of policy and institutions on individual agents. Second, economics offers a rich literature on the nature of unplanned order and how it might be shaped by policy. Third, economics offers insight into the public and private provision of various kinds of goods (private, public, common pool resources). Fourth, recent work on the development and logic of institutions and norms emphasizes sustainability rooted in the good of the individual.

Biosynthetic strategies for tetramic acid formation

2021 ◽  
Author(s):  
Xuhua Mo ◽  
Tobias A. M. Gulder
Keyword(s):  
Molecular Mechanism ◽  
Gene Clusters ◽  
Acid Formation ◽  
Biosynthetic Gene ◽  
Tetramic Acid ◽  
Biosynthetic Gene Clusters ◽  
The Individual ◽  
First Time ◽  
Acid Unit

Over 30 biosynthetic gene clusters for natural tetramate have been identified. This highlight reviews the biosynthetic strategies for formation of tetramic acid unit for the first time, discussing the individual molecular mechanism in detail.

scholarly journals Intra-Colonial Viral Infections in Western Honey Bees (Apis mellifera)

2021 ◽  
Vol 9 (5) ◽  
pp. 1087
Author(s):  
Loreley Castelli ◽  
María Laura Genchi García ◽  
Anne Dalmon ◽  
Daniela Arredondo ◽  
Karina Antúnez ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Viral Infections ◽  
Sampling Period ◽  
Virus Genome ◽  
The Individual ◽  
Bee Virus ◽  
Insight Into ◽  
Bee Viruses

RNA viruses play a significant role in the current high losses of pollinators. Although many studies have focused on the epidemiology of western honey bee (Apis mellifera) viruses at the colony level, the dynamics of virus infection within colonies remains poorly explored. In this study, the two main variants of the ubiquitous honey bee virus DWV as well as three major honey bee viruses (SBV, ABPV and BQCV) were analyzed from Varroa-destructor-parasitized pupae. More precisely, RT-qPCR was used to quantify and compare virus genome copies across honey bee pupae at the individual and subfamily levels (i.e., patrilines, sharing the same mother queen but with different drones as fathers). Additionally, virus genome copies were compared in cells parasitized by reproducing and non-reproducing mite foundresses to assess the role of this vector. Only DWV was detected in the samples, and the two variants of this virus significantly differed when comparing the sampling period, colonies and patrilines. Moreover, DWV-A and DWV-B exhibited different infection patterns, reflecting contrasting dynamics. Altogether, these results provide new insight into honey bee diseases and stress the need for more studies about the mechanisms of intra-colonial disease variation in social insects.

scholarly journals Individualized Hemodynamic Management in Sepsis

2021 ◽  
Vol 11 (2) ◽  
pp. 157
Author(s):  
Marcell Virág ◽  
Tamas Leiner ◽  
Mate Rottler ◽  
Klementina Ocskay ◽  
Zsolt Molnar
Keyword(s):  
Fluid Overload ◽  
Fluid Management ◽  
Multiple Organ ◽  
Treatment Protocols ◽  
Hemodynamic Management ◽  
New Approach ◽  
Hemodynamic Optimization ◽  
The Individual ◽  
Sepsis And Septic Shock ◽  
Insight Into

Hemodynamic optimization remains the cornerstone of resuscitation in the treatment of sepsis and septic shock. Delay or inadequate management will inevitably lead to hypoperfusion, tissue hypoxia or edema, and fluid overload, leading eventually to multiple organ failure, seriously affecting outcomes. According to a large international survey (FENICE study), physicians frequently use inadequate indices to guide fluid management in intensive care units. Goal-directed and “restrictive” infusion strategies have been recommended by guidelines over “liberal” approaches for several years. Unfortunately, these “fixed regimen” treatment protocols neglect the patient’s individual needs, and what is shown to be beneficial for a given population may not be so for the individual patient. However, applying multimodal, contextualized, and personalized management could potentially overcome this problem. The aim of this review was to give an insight into the pathophysiological rationale and clinical application of this relatively new approach in the hemodynamic management of septic patients.

scholarly journals Discoloration of Historical Plastic Objects: New Insight into the Degradation of β-Naphthol Pigment Lakes

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2278
Author(s):  
Anna Micheluz ◽  
Eva Mariasole Angelin ◽  
João Almeida Lopes ◽  
Maria João Melo ◽  
Marisa Pamplona
Keyword(s):  
Light Exposure ◽  
Molecular Structures ◽  
Conservation Science ◽  
Organic Pigment ◽  
Organic Pigments ◽  
Before And After ◽  
The Individual ◽  
Determining Factor ◽  
Insight Into ◽  
Historical Samples

Light is a determining factor in the discoloration of plastics, and photodegradation processes can affect the molecular structures of both the polymer and colorants. Limited studies focused on the discoloration of heritage plastics in conservation science. This work investigated the discoloration of red historical polyethylene (PE) objects colored with PR 48:2 and PR 53:1. High-density and low-density PE reference polymers, neat pigment powders, and historical samples were assessed before and after accelerated photoaging. The applied methodology provided insight into the individual light-susceptibility of polyethylenes, organic pigment lakes, and their combined effect in the photoaging of historical plastic formulations. After light exposure, both PE references and historical samples yellowed, PR53:1 faded, and PR 48:2 darkened; however, both organic pigments faded severely in the historical samples. This highlights the role played by the plastic binder likely facilitating the pigment photofading. Fourier transform infrared spectroscopy and mass spectrometry techniques—EGA-MS, PY-GC/MS, and TD-GC/MS—were successfully employed for characterizing the plastic formulations and degradation. The identification of phthalic compounds in both aged β-naphthol powders opens new venues for studies on their degradation. This work’s approach and analytical methods in studying the discoloration of historical plastics are novel, proving their efficacy, reliability, and potentiality.

Insight Into The Molecular Basis Of The Anti‑Hyperglycemic Activity Of Ra‑3 In Type 2 Diabetic Rats And Its Cardioprotective Potential In Cultured Cardiomyoblasts

Metabolism ◽  
2021 ◽  
Vol 116 ◽  
pp. 154646
Author(s):  
R.A. Mosa ◽  
S.E. Mabhida ◽  
N.F. Sangweni ◽  
P.V. Dludla ◽  
A.R. Opoku ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Diabetic Rats ◽  
Type 2 Diabetic ◽  
Insight Into
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