Revealing the promoting effect of betaine on vitamin B12 biosynthetic pathway of Pseudomonas denitrificans by using a proteomics analysis

2021 ◽  
Vol 22 ◽  
Author(s):  
Kun-tai Li ◽  
Yong Yang ◽  
Xin Cheng
Keyword(s):  
Vitamin B12 ◽  
Biosynthetic Pathway ◽  
Aminolevulinic Acid ◽  
Fermentation Medium ◽  
Promoting Effect ◽  
Pseudomonas Denitrificans ◽  
Methyl Group ◽  
Integral Effect ◽  
Comparative Metabolomics ◽  
Porphobilinogen Synthase

Background: Our previous comparative metabolomics research revealed that betaine (N,N,N-trimethylglycine, a typically essential methyl-group donor for vitamin B12 biosynthesis) had a powerful promoting effect on the generation of vitamin B12 precursors and intermediates in vitamin B12-producing Pseudomonas denitrificans. However, the integral effect of betaine on the vitamin B12 biosynthetic pathway is still unclear. Objective: Considering the vitamin B12 biosynthetic pathway of P. denitrificans as a whole, this work aimed to reveal the biological function of betaine on the vitamin B12 biosynthetic pathway in P. denitrificans, which would sharpen and expand the understanding of betaine as the methyl-group donor for vitamin B12 biosynthesis. Materials and Methods: By using a proteomics method based on the iTRAQ technique, the present study compared and analyzed the differential expression of proteins involved in vitamin B12 biosynthetic pathway under 10 g/L betaine addition to P. denitrificans fermentation medium. Results: The results showed that betaine could significantly up-regulate the expression of proteins related to the vitamin B12 biosynthetic pathway, which was mainly reflected in the following three aspects: 1) the δ-aminolevulinic acid (ALA) synthase and porphobilinogen synthase that were responsible for the formation of the committed precursors for tetrapyrrole-derived macrocycle in vitamin B12 molecule; 2) the C-methylation-related enzymes (such as precorrin-4 C(11)-methyltransferase, Precorrin-2 C(20)-methyltransferase, Precorrin-8X methylmutase, and Precorrin-6Y C5,15-methyltransferase) and methionine synthase that were crucial to the C-methylation reactions for vitamin B12 biosynthesis; 3) the late-stage key enzymes (Cobaltochelatase, and Cob(I)yrinic acid a,c-diamide adenosyltransferase) that were related to cobalt chelation of vitamin B12 molecule. Conclusions: The present study clearly demonstrated that betaine could significantly promote the expression of the integral enzymes involved in the vitamin B12 biosynthetic pathway of P. denitrificans, thus promoting vitamin B12 biosynthesis.

scholarly journals Biosynthesis of vitamin B12: the preparative multi-enzyme synthesis of precorrin-3A and 20-methylsirohydrochlorin (a 2,7,20-trimethylisobacteriochlorin)

1996 ◽  
Vol 313 (1) ◽  
pp. 335-342 ◽  
Author(s):  
N. J. Patrick STAMFORD ◽  
Joël CROUZET ◽  
Béatrice CAMERON ◽  
Alex I. D. ALANINE ◽  
Andrew R. PITT ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Large Scale ◽  
Enzyme Preparation ◽  
Enzyme System ◽  
Enzyme Synthesis ◽  
High Yield ◽  
Pseudomonas Denitrificans ◽  
E Coli ◽  
Plasmid Construct ◽  
Porphobilinogen Synthase

The Bacillus subtilis genes hemB, hemC and hemD, encoding respectively the enzymes porphobilinogen synthase, hydroxymethylbilane synthase and uroporphyrinogen III synthase, have been expressed in Escherichia coli using a single plasmid construct. An enzyme preparation from this source converts 5-aminolaevulinic acid (ALA) preparatively and in high yield into uroporphyrinogen III. The Pseudomonas denitrificans genes cobA and cobI, encoding respectively the enzymes S-adenosyl-L-methionine:uroporphyrinogen III methyltransferase (SUMT) and S-adenosyl-L-methionine:precorrin-2 methyltransferase (SP2MT), were also expressed in E. coli. When SUMT was combined with the coupled-enzyme system that produces uroporphyrinogen III, precorrin-2 was synthesized from ALA, and when SP2MT was also added the product from the coupling of five enzymes was precorrin-3A. Both of these products are precursors of vitamin B12, and they can be used directly for biosynthetic experiments or isolated as their didehydro octamethyl esters in > 40% overall yield. The enzyme system which produces precorrin-3A is sufficiently stable to allow long incubations on a large scale, affording substantial quantities (15-20 mg) of product.

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 Novel insights into the m6A-RNA methyltransferase METTL3 in cancer

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Yiqing Cai ◽  
Rui Feng ◽  
Tiange Lu ◽  
Xiaomin Chen ◽  
Xiangxiang Zhou ◽  
...  
Keyword(s):  
Poor Prognosis ◽  
Human Cancer ◽  
Rna Modification ◽  
Rapid Progression ◽  
Antitumor Therapy ◽  
Promoting Effect ◽  
Methyl Group ◽  
Group Transfer ◽  
Functional Regulation ◽  
Methyl Group Transfer

AbstractN6-methyladenosine (m6A) is a prevalent internal RNA modification in higher eukaryotic cells. As the pivotal m6A regulator, RNA methyltransferase-like 3 (METTL3) is responsible for methyl group transfer in the progression of m6A modification. This epigenetic regulation contributes to the structure and functional regulation of RNA and further promotes tumorigenesis and tumor progression. Accumulating evidence has illustrated the pivotal roles of METTL3 in a variety of human cancers. Here, we systemically summarize the interaction between METTL3 and RNAs, and illustrate the multiple functions of METTL3 in human cancer. METLL3 is aberrantly expressed in a variety of tumors. Elevation of METTL3 is usually associated with rapid progression and poor prognosis of tumors. On the other hand, METTL3 may also function as a tumor suppressor in several cancers. Based on the tumor-promoting effect of METTL3, the possibility of applying METTL3 inhibitors is further discussed, which is expected to provide novel insights into antitumor therapy.

Vitamin B12 and methyl-group synthesis

1957 ◽  
Vol 11 (3) ◽  
pp. 313-323 ◽  
Author(s):  
B. Connor Johnson ◽  
E. S. Holdsworth ◽  
J. W. G. Porter ◽  
S. K. Kon
Keyword(s):  
Vitamin B12 ◽  
Methyl Group

scholarly journals Recognized and Emerging Features of Erythropoietic and X-Linked Protoporphyria

Diagnostics ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 151
Author(s):  
Elena Di Pierro ◽  
Francesca Granata ◽  
Michele De Canio ◽  
Mariateresa Rossi ◽  
Andrea Ricci ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Aminolevulinic Acid ◽  
Protoporphyrin Ix ◽  
Limiting Factor ◽  
Zinc Protoporphyrin ◽  
Complete Understanding ◽  
Inherited Disorders ◽  
Rate Limiting ◽  
Systemic Accumulation ◽  
Made In

Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are inherited disorders resulting from defects in two different enzymes of the heme biosynthetic pathway, i.e., ferrochelatase (FECH) and delta-aminolevulinic acid synthase-2 (ALAS2), respectively. The ubiquitous FECH catalyzes the insertion of iron into the protoporphyrin ring to generate the final product, heme. After hemoglobinization, FECH can utilize other metals like zinc to bind the remainder of the protoporphyrin molecules, leading to the formation of zinc protoporphyrin. Therefore, FECH deficiency in EPP limits the formation of both heme and zinc protoporphyrin molecules. The erythroid-specific ALAS2 catalyses the synthesis of delta-aminolevulinic acid (ALA), from the union of glycine and succinyl-coenzyme A, in the first step of the pathway in the erythron. In XLP, ALAS2 activity increases, resulting in the amplified formation of ALA, and iron becomes the rate-limiting factor for heme synthesis in the erythroid tissue. Both EPP and XLP lead to the systemic accumulation of protoporphyrin IX (PPIX) in blood, erythrocytes, and tissues causing the major symptom of cutaneous photosensitivity and several other less recognized signs that need to be considered. Although significant advances have been made in our understanding of EPP and XLP in recent years, a complete understanding of the factors governing the variability in clinical expression and the severity (progression) of the disease remains elusive. The present review provides an overview of both well-established facts and the latest findings regarding these rare diseases.

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