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.

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 Lysine Represses Transcription of the Escherichia coli dapB Gene by Preventing Its Activation by the ArgP Activator

2008 ◽  
Vol 190 (15) ◽  
pp. 5224-5229 ◽  
Author(s):  
Jean Bouvier ◽  
Patrick Stragier ◽  
Violette Morales ◽  
Elisabeth Rémy ◽  
Claude Gutierrez
Keyword(s):  
Escherichia Coli ◽  
Transcription Start Site ◽  
Biosynthetic Pathway ◽  
Genomic Library ◽  
Regulatory Region ◽  
Null Mutation ◽  
Start Site ◽  
Transcription Start ◽  
Gene Encoding ◽  
Gel Retardation Assay

ABSTRACT The Escherichia coli dapB gene encodes one of the enzymes of the biosynthetic pathway leading to lysine and its immediate precursor, diaminopimelate. Expression of dapB is repressed by lysine, but no trans-acting regulator has been identified so far. Our analysis of the dapB regulatory region shows that sequences located in the −81/−118 interval upstream of the transcription start site are essential for full expression of dapB, as well as for lysine repression. Screening a genomic library for a gene that could alleviate lysine repression when present in multicopy led to the recovery of argP, a gene encoding an activating protein of the LysR-type family, known to use lysine as an effector. An argP null mutation strongly decreases dapB transcription that becomes insensitive to lysine. Purified His6-tagged ArgP protein binds with an apparent K d of 35 nM to the dapB promoter in a gel retardation assay, provided that sequences up to −103 are present. In the presence of l-lysine and l-arginine, the binding of ArgP to dapB is partly relieved. These results fit with a model in which ArgP contributes to enhanced transcription of dapB when lysine becomes limiting.

scholarly journals Inactivation of the ampDE Operon Increases Transcription of algD and Affects Morphology and Encystment of Azotobacter vinelandii

2000 ◽  
Vol 182 (17) ◽  
pp. 4829-4835 ◽  
Author(s):  
Cinthia Núñez ◽  
Soledad Moreno ◽  
Luis Cárdenas ◽  
Gloria Soberón-Chávez ◽  
Guadalupe Espín
Keyword(s):  
Escherichia Coli ◽  
Biosynthetic Pathway ◽  
Azotobacter Vinelandii ◽  
Transmembrane Protein ◽  
Nucleotide Sequencing ◽  
Insertion Mutant ◽  
Gene Encoding ◽  
Alginate Production ◽  
Key Enzyme

ABSTRACT Transcription of algD, encoding GDP-mannose dehydrogenase, the key enzyme in the alginate biosynthetic pathway, is highly regulated in Azotobacter vinelandii. We describe here the characterization of a Tn5 insertion mutant (AC28) which shows a higher level of expression of analgD::lacZ fusion. AC28 cells were morphologically abnormal and unable to encyst. The cloning and nucleotide sequencing of the Tn5-disrupted locus in AC28 revealed an operon homologous to the Escherichia coli ampDEoperon. Tn5 was located within the ampD gene, encoding a cytosolicN-acetyl-anhydromuramyl-l-alanine amidase that participates in the intracellular recycling of peptidoglycan fragments. The ampE gene encodes a transmembrane protein, but the function of the protein is not known. We constructed strains carryingampD or ampE mutations and one with anampDE deletion. The strain with a deletion of theampDE operon showed a phenotype similar to that of mutant AC28. The present work demonstrates that both alginate production and bacterial encystment are greatly influenced by the bacterial ability to recycle its cell wall.

scholarly journals Genome Mining Reveals Two Missing CrtP and AldH Enzymes in the C30 Carotenoid Biosynthesis Pathway in Planococcus faecalis AJ003T

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5892
Author(s):  
Jun Ho Lee ◽  
Jin Won Kim ◽  
Pyung Cheon Lee
Keyword(s):  
Escherichia Coli ◽  
Biosynthetic Pathway ◽  
Genome Mining ◽  
Carotenoid Biosynthesis ◽  
Biosynthesis Pathway ◽  
Gene Encoding ◽  
A Genome ◽  
Genes Encoding ◽  
Carotenoid Biosynthesis Pathway ◽  
Carotenoid Pathway

Planococcus faecalis AJ003T produces glycosyl-4,4′-diaponeurosporen-4′-ol-4-oic acid as its main carotenoid. Five carotenoid pathway genes were presumed to be present in the genome of P. faecalis AJ003T; however, 4,4-diaponeurosporene oxidase (CrtP) was non-functional, and a gene encoding aldehyde dehydrogenase (AldH) was not identified. In the present study, a genome mining approach identified two missing enzymes, CrtP2 and AldH2454, in the glycosyl-4,4′-diaponeurosporen-4′-ol-4-oic acid biosynthetic pathway. Moreover, CrtP2 and AldH enzymes were functional in heterologous Escherichia coli and generated two carotenoid aldehydes (4,4′-diapolycopene-dial and 4,4′-diaponeurosporene-4-al) and two carotenoid carboxylic acids (4,4′-diaponeurosporenoic acid and 4,4′-diapolycopenoic acid). Furthermore, the genes encoding CrtP2 and AldH2454 were located at a distance the carotenoid gene cluster of P. faecalis.

scholarly journals The Drosophila molybdenum cofactor gene cinnamon is homologous to three Escherichia coli cofactor proteins and to the rat protein gephyrin.

Genetics ◽  
1994 ◽  
Vol 137 (3) ◽  
pp. 791-801 ◽  
Author(s):  
K P Kamdar ◽  
M E Shelton ◽  
V Finnerty
Keyword(s):  
Escherichia Coli ◽  
Central Nervous System ◽  
Biosynthetic Pathway ◽  
Sequence Similarity ◽  
Molybdenum Cofactor ◽  
Side Chain ◽  
Gene Encoding ◽  
Multifunctional Protein ◽  
Cofactor Biosynthesis ◽  
Higher Eukaryotes

Abstract Essentially all organisms depend upon molybdenum oxidoreductases which require a molybdopterin cofactor for catalytic activity. Mutations resulting in a lack of the cofactor show a pleiotropic loss of molybdoenzyme activities and thereby define genes involved in cofactor biosynthesis or utilization. In prokaryotes, two operons are directly associated with biosynthesis of the pterin moiety and its side chain while additional loci play a role in the acquisition of molybdenum and/or activation of the cofactor. Here we report the cloning of cinnamon, a Drosophila molybdenum cofactor gene encoding a protein with sequence similarity to three of the prokaryotic cofactor proteins. In addition, the Drosophila cinnamon protein is homologous to gephyrin, a protein isolated from the rat central nervous system. Our results suggest that some portions of the prokaryotic cofactor biosynthetic pathway composed of monofunctional proteins have evolved into a multifunctional protein in higher eukaryotes.

scholarly journals Analysis of the upstream region of the Escherichia coli rnd gene encoding RNase D

1989 ◽  
Vol 264 (30) ◽  
pp. 18228-18233
Author(s):  
J R Zhang ◽  
M P Deutscher
Keyword(s):  
Escherichia Coli ◽  
Upstream Region ◽  
Gene Encoding

scholarly journals Substrate‐activated expression of a biosynthetic pathway in Escherichia coli

2021 ◽  
pp. 2000433
Author(s):  
Cynthia Ni ◽  
Kevin J. Fox ◽  
Kristala L. J. Prather
Keyword(s):  
Escherichia Coli ◽  
Biosynthetic Pathway
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