scholarly journals Plasmodium falciparum hydroxymethylbilane synthase does not house any cosynthase activity within the haem biosynthetic pathway

2021 ◽  
Author(s):  
Alan F. Scott ◽  
Evelyne Deery ◽  
Andrew D. Lawrence ◽  
Martin J. Warren
Keyword(s):  
Plasmodium Falciparum ◽  
Hplc Analysis ◽  
Biosynthetic Pathway ◽  
Gene Encoding ◽  
E Coli ◽  
Aminolaevulinic Acid ◽  
Porphobilinogen Synthase

AbstractThe production of uroporphyrinogen III, the universal progenitor of macrocyclic, modified tetrapyrroles, is produced from aminolaevulinic acid (ALA) by a conserved pathway involving three enzymes: porphobilinogen synthase (PBGS), hydroxymethylbilane synthase (HmbS) and uroporphyrinogen III synthase (UroS). The gene encoding uroporphyrinogen III synthase has not yet been identified in Plasmodium falciparum but it has been suggested that this activity is housed inside a bifunctional hybroxymethylbilane synthase (HmbS). In this present study it is demonstrated that P. falciparum HmbS does not have uroporphyrinogen III synthase activity. This was demonstrated by the failure of a codon optimised P. falciparum hemC gene, encoding HmbS, to compliment a defined E. coli hemD- mutant (SASZ31) deficient in uroporphyrinogen III synthase activity. Furthermore, HPLC analysis of the oxidsed reaction product from recombinant, purified HmbS showed that only uroporphyrin I could be detected (corresponding to hydroxymethylbilane production). No uroporphyrin III was detected, thus showing that P. falciparum HmbS does not have UroS activity and can only catalyse the formation of hydroxymethylbilane from porphobilinogen.

scholarly journals Plasmodium falciparum hydroxymethylbilane synthase does not house any cosynthase activity within the haem biosynthetic pathway

Microbiology ◽  
2021 ◽  
Vol 167 (10) ◽  
Author(s):  
Alan F. Scott ◽  
Evelyne Deery ◽  
Andrew D. Lawrence ◽  
Martin J. Warren
Keyword(s):  
Escherichia Coli ◽  
Plasmodium Falciparum ◽  
Hplc Analysis ◽  
Biosynthetic Pathway ◽  
Gene Encoding ◽  
The Real ◽  
Aminolaevulinic Acid ◽  
Unknown Protein ◽  
Porphobilinogen Synthase

Uroporphyrinogen III, the universal progenitor of macrocyclic, modified tetrapyrroles, is produced from aminolaevulinic acid (ALA) by a conserved pathway involving three enzymes: porphobilinogen synthase (PBGS), hydroxymethylbilane synthase (HmbS) and uroporphyrinogen III synthase (UroS). The gene encoding uroporphyrinogen III synthase has not yet been identified in Plasmodium falciparum, but it has been suggested that this activity is housed inside a bifunctional hybroxymethylbilane synthase (HmbS). Additionally, an unknown protein encoded by PF3D7_1247600 has also been predicted to possess UroS activity. In this study it is demonstrated that neither of these proteins possess UroS activity and the real UroS remains to be identified. This was demonstrated by the failure of codon-optimized genes to complement a defined Escherichia coli hemD − mutant (SASZ31) deficient in UroS activity. Furthermore, HPLC analysis of the oxidized reaction product from recombinant, purified P. falciparum HmbS showed that only uroporphyrin I could be detected (corresponding to hydroxymethylbilane production). No uroporphyrin III was detected, showing that P. falciparum HmbS does not have UroS activity and can only catalyze the formation of hydroxymethylbilane from porphobilinogen.

Cloning and sequence analysis of the hemB gene of Staphylococcus aureus

1994 ◽  
Vol 40 (8) ◽  
pp. 651-657 ◽  
Author(s):  
Badria Kafala ◽  
A. Sasarman
Keyword(s):  
Staphylococcus Aureus ◽  
Biosynthetic Pathway ◽  
Aminolevulinic Acid ◽  
Colony Growth ◽  
Reading Frame ◽  
E Coli ◽  
Preliminary Identification ◽  
The Family ◽  
Genes Encoding ◽  
Porphobilinogen Synthase

The hemB gene is a member of the family of genes encoding enzymes of the porphyrin biosynthetic pathway and codes for the enzyme porphobilinogen synthase, which is responsible for the conversion of Δ-aminolevulinic acid to porphobilinogen. To clone the hemB gene of Staphylococcus aureus we used Tn917-mediated transposon mutagenesis. Tn917 confers resistance to erythromycin and is carried by plasmid pTV1ts, which has thermosensitive replication. Hem mutants were selected by growth in the presence of kanamycin and erythromycin at 43 °C. Preliminary identification of the hem mutants was based on their dwarf colony growth, which could be restored to normal by hemin. DNA extracted from one of the hem mutants was digested with several restriction endonucleases and hybridized to a probe representing the XbaI–AvaI end of Tn917. A BglII–EcoRI fragment of 4.5 kb gave a positive signal and was cloned into pUC18. Transformants were identified by colony hybridization with the Tn917 probe. The positive clones were sequenced, starting from the transposon end. The results allowed us to identify an open reading frame whose nucleotide sequence presented a homology of 63% to the sequence of the hemB gene of Bacillus subtilis and of 55% to the sequence of the hemB gene of Escherichia coli K12. No other nucleotide sequences, except those belonging to known hemB genes, presented significant homologies to our sequence. The cloning of the hemB gene of S. aureus was confirmed by the ability of the gene to complement a hemB mutant of E. coli K12. To our knowledge, this is the first report of the cloning of a hem gene in S. aureus.Key words: Δ-aminolevulinic acid dehydratase, hemB gene, S. aureus, heme, porphyrins.

scholarly journals The panE Gene, Encoding Ketopantoate Reductase, Maps at 10 Minutes and Is Allelic to apbA inSalmonella typhimurium

1998 ◽  
Vol 180 (17) ◽  
pp. 4757-4759 ◽  
Author(s):  
Michael E. Frodyma ◽  
Diana Downs
Keyword(s):  
Biosynthetic Pathway ◽  
De Novo ◽  
Biosynthetic Gene ◽  
Gene Encoding ◽  
E Coli ◽  
In Vivo Labeling ◽  
Pyrimidine Moiety ◽  
Pantoic Acid

ABSTRACT In Salmonella typhimurium, precursors to the pyrimidine moiety of thiamine are synthesized de novo by the purine biosynthetic pathway or the alternative pyrimidine biosynthetic (APB) pathway. TheapbA gene was the first locus defined as required for function of the APB pathway (D. M. Downs and L. Petersen, J. Bacteriol. 176:4858–4864, 1994). Recent work showed the ApbA protein catalyzes the NADPH-specific reduction of ketopantoic acid to pantoic acid. This activity had previously been associated with the pantothenate biosynthetic gene panE. Although previous reports placed panE at 87 min on the Escherichia coli chromosome, we show herein that apbA andpanE are allelic and map to 10 min on both the S. typhimurium and E. coli chromosomes. Results presented here suggest that the role of ApbA in thiamine synthesis is indirect since in vivo labeling studies showed that pantoic acid, the product of the ApbA-catalyzed reaction, is not a direct precursor to thiamine via the APB pathway.

scholarly journals Biosynthetic pathways and enzymes involved in the production of phosphonic acid natural products

2021 ◽  
Vol 85 (1) ◽  
pp. 42-52
Author(s):  
Taro Shiraishi ◽  
Tomohisa Kuzuyama
Keyword(s):  
Natural Products ◽  
Biosynthetic Pathway ◽  
Organophosphorus Compounds ◽  
Genome Mining ◽  
Biological Molecules ◽  
Antibacterial Drug ◽  
Gene Encoding ◽  
Quarter Century ◽  
Lead Compounds ◽  
Biosynthetic Machinery

Abstract Phosphonates are organophosphorus compounds possessing a characteristic C−P bond in which phosphorus is directly bonded to carbon. As phosphonates mimic the phosphates and carboxylates of biological molecules to potentially inhibit metabolic enzymes, they could be lead compounds for the development of a variety of drugs. Fosfomycin (FM) is a representative phosphonate natural product that is widely used as an antibacterial drug. Here, we review the biosynthesis of FM, which includes a recent breakthrough to find a missing link in the biosynthetic pathway that had been a mystery for a quarter-century. In addition, we describe the genome mining of phosphonate natural products using the biosynthetic gene encoding an enzyme that catalyzes C–P bond formation. We also introduce the chemoenzymatic synthesis of phosphonate derivatives. These studies expand the repertoires of phosphonates and the related biosynthetic machinery. This review mainly covers the years 2012-2020.

scholarly journals Kelch 13-propeller polymorphisms in Plasmodium falciparum from Jazan region, southwest Saudi Arabia

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Ommer Mohammed Dafalla ◽  
Mohammed Alzahrani ◽  
Ahmed Sahli ◽  
Mohammed Abdulla Al Helal ◽  
Mohammad Mohammad Alhazmi ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Saudi Arabia ◽  
Parasite Clearance ◽  
Sub Saharan Africa ◽  
Local Alignment ◽  
Nucleotide Polymorphisms ◽  
Gene Encoding ◽  
Synonymous Mutations ◽  
Search Tool ◽  
Sub Saharan

Abstract Background Artemisinin-based combination therapy (ACT) is recommended at the initial phase for treatment of Plasmodium falciparum, to reduce morbidity and mortality in all countries where malaria is endemic. Polymorphism in portions of P. falciparum gene encoding kelch (K13)-propeller domains is associated with delayed parasite clearance after ACT. Of about 124 different non-synonymous mutations, 46 have been identified in Southeast Asia (SEA), 62 in sub-Saharan Africa (SSA) and 16 in both the regions. This is the first study designed to analyse the prevalence of polymorphism in the P. falciparum k13-propeller domain in the Jazan region of southwest Saudi Arabia, where malaria is endemic. Methods One-hundred and forty P. falciparum samples were collected from Jazan region of southwest Saudi Arabia at three different times: 20 samples in 2011, 40 samples in 2016 and 80 samples in 2020 after the implementation of ACT. Plasmodium falciparum kelch13 (k13) gene DNA was extracted, amplified, sequenced, and analysed using a basic local alignment search tool (BLAST). Results This study obtained 51 non-synonymous (NS) mutations in three time groups, divided as follows: 6 single nucleotide polymorphisms (SNPs) ‘11.8%’ in samples collected in 2011 only, 3 (5.9%) in 2011and 2016, 5 (9.8%) in 2011 and 2020, 5 (9.8%) in 2016 only, 8 (15.7%) in 2016 and 2020, 14 (27.5%) in 2020 and 10 (19.6%) in all the groups. The BLAST revealed that the 2011 isolates were genetically closer to African isolates (53.3%) than Asian ones (46.7%). Interestingly, this proportion changed completely in 2020, to become closer to Asian isolates (81.6%) than to African ones (18.4%). Conclusions Despite the diversity of the identified mutations in the k13-propeller gene, these data did not report widespread artemisinin-resistant polymorphisms in the Jazan region where these samples were collected. Such a process would be expected to increase frequencies of mutations associated with the resistance of ACT.

scholarly journals Identification and Characterization of a New Enoyl Coenzyme A Hydratase Involved in Biosynthesis of Medium-Chain-Length Polyhydroxyalkanoates in Recombinant Escherichia coli

2003 ◽  
Vol 185 (18) ◽  
pp. 5391-5397 ◽  
Author(s):  
Si Jae Park ◽  
Sang Yup Lee
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid ◽  
Chain Length ◽  
Biosynthetic Pathway ◽  
Pha Synthase ◽  
Enzymatic Analysis ◽  
E Coli ◽  
Medium Chain ◽  
Medium Chain Length ◽  
Enoyl Coa Hydratase

ABSTRACT The biosynthetic pathway of medium-chain-length (MCL) polyhydroxyalkanoates (PHAs) from fatty acids has been established in fadB mutant Escherichia coli strain by expressing the MCL-PHA synthase gene. However, the enzymes that are responsible for the generation of (R)-3-hydroxyacyl coenzyme A (R3HA-CoAs), the substrates for PHA synthase, have not been thoroughly elucidated. Escherichia coli MaoC, which is homologous to Pseudomonas aeruginosa (R)-specific enoyl-CoA hydratase (PhaJ1), was identified and found to be important for PHA biosynthesis in a fadB mutant E. coli strain. When the MCL-PHA synthase gene was introduced, the fadB maoC double-mutant E. coli WB108, which is a derivative of E. coli W3110, accumulated 43% less amount of MCL-PHA from fatty acid compared with the fadB mutant E. coli WB101. The PHA biosynthetic capacity could be restored by plasmid-based expression of the maoCEc gene in E. coli WB108. Also, E. coli W3110 possessing fully functional β-oxidation pathway could produce MCL-PHA from fatty acid by the coexpression of the maoCEc gene and the MCL-PHA synthase gene. For the enzymatic analysis, MaoC fused with His6-Tag at its C-terminal was expressed in E. coli and purified. Enzymatic analysis of tagged MaoC showed that MaoC has enoyl-CoA hydratase activity toward crotonyl-CoA. These results suggest that MaoC is a new enoyl-CoA hydratase involved in supplying (R)-3-hydroxyacyl-CoA from the β-oxidation pathway to PHA biosynthetic pathway in the fadB mutant E. coli strain.

scholarly journals Pathogen and Pest Responses Are Altered Due to RNAi-Mediated Knockdown of GLYCOALKALOID METABOLISM 4 in Solanum tuberosum

2017 ◽  
Vol 30 (11) ◽  
pp. 876-885 ◽  
Author(s):  
Jamuna Risal Paudel ◽  
Charlotte Davidson ◽  
Jun Song ◽  
Itkin Maxim ◽  
Asaph Aharoni ◽  
...  
Keyword(s):  
Solanum Tuberosum ◽  
Biosynthetic Pathway ◽  
Plant Protection ◽  
Insect Pest ◽  
Metabolite Profile ◽  
Gene Encoding ◽  
Rnai Line ◽  
Leaf Consumption ◽  
Insect Mortality ◽  
Potato Growth

Steroidal glycoalkaloids (SGAs) are major secondary metabolites constitutively produced in cultivated potato Solanum tuberosum, and α-solanine and α-chaconine are the most abundant SGAs. SGAs are toxic to humans at high levels but their role in plant protection against pests and pathogens is yet to be established. In this study, levels of SGAs in potato were reduced by RNA interference (RNAi)-mediated silencing of GLYCOALKALOID METABOLISM 4 (GAME4)—a gene encoding cytochrome P450, involved in an oxidation step in the conversion of cholesterol to SGA aglycones. Two GAME4 RNAi lines, T8 and T9, were used to investigate the effects of manipulation of the SGA biosynthetic pathway in potato. Growth and development of an insect pest, Colorado potato beetle (CPB), were affected in these lines. While no effect on CPB leaf consumption or weight gain was observed, early instar larval death and accelerated development of the insect was found while feeding on leaves of GAME4 RNAi lines. Modulation of SGA biosynthetic pathway in GAME4 RNAi plants was associated with a larger alteration to the metabolite profile, including increased levels of one or both the steroidal saponins or phytoecdysteroids, which could affect insect mortality as well as development time. Colonization by Verticillium dahliae on GAME4 RNAi plants was also tested. There were increased pathogen levels in the T8 GAME4 RNAi line but not in the T9. Metabolite differences between T8 and T9 were found and may have contributed to differences in V. dahliae infection. Drought responses created by osmotic stress were not affected by modulation of SGA biosynthetic pathway in potato.

Effect of tamoxifen on the sphingolipid biosynthetic pathway in the different intraerythrocytic stages of the apicomplexa Plasmodium falciparum

2018 ◽  
Vol 497 (4) ◽  
pp. 1082-1088 ◽  
Author(s):  
Tamara A. Piñero ◽  
Malena Landoni ◽  
Vilma G. Duschak ◽  
Alejandro M. Katzin ◽  
Alicia S. Couto
Keyword(s):  
Plasmodium Falciparum ◽  
Biosynthetic Pathway
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