Structural genes for thiamine biosynthetic enzymes (thiCEFGH) in Escherichia coli K-12

Horn, P B Vander; Backstrom, Allyson D.; Stewart, Valley; Begley, Tadhg P.

doi:10.1128/jb.175.4.982-992.1993

Cited by 113 publications

(132 citation statements)

References 39 publications

Supporting

Mentioning

125

Contrasting

Unclassified

Order By: Relevance

“…Early research has suggested that the thiamine biosynthesis of plants is similar to that of microorganisms [24,36]. In E. coli, thiamine is synthesized by coupling HET-P (4-methyl-5-β-hydroxyethylthiazole phosphate) with HMP-PP (4-amino-5-hydroxymethylpyrimidine pyrophosphate) catalysed by ThiE (a thiamine phosphate synthase) [15,18,20,21] (Figure 1). HET-P (thiazole moiety) and HMP-PP (pyrimidine moiety) are synthesized separately under the influence of different genes [24,27].…”

Section: Discussionmentioning

confidence: 99%

“…The pyrimidine unit is synthesized from AIR (5-aminoimidazole ribotide), and ThiC is re-quired for pyrimidine biosynthesis [14][15][16][17] (Figure 1). Subsequently, ThiE, a thiamine phosphate synthase, couples the two ring structures of pyrimidine and thiazole to form TP [9,[17][18][19][20] (Figure 1). Further, ThiL catalyses TP to form TPP [10,21].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

AtTHIC, a gene involved in thiamine biosynthesis in Arabidopsis thaliana

Kong

Zhu

et al. 2008

Cell Res

View full text Add to dashboard Cite

Thiamine (vitamin B1) is an essential compound for organisms. It contains a pyrimidine ring structure and a thiazole ring structure. These two moieties of thiamine are synthesized independently and then coupled together. Here we report the molecular characterization of AtTHIC, which is involved in thiamine biosynthesis in Arabidopsis. AtTHIC is similar to Escherichia coli ThiC, which is involved in pyrimidine biosynthesis in prokaryotes. Heterologous expression of AtTHIC could functionally complement the thiC knock-out mutant of E. coli. Downregulation of AtTHIC expression by T-DNA insertion at its promoter region resulted in a drastic reduction of thiamine content in plants and the knock-down mutant thic1 showed albino (white leaves) and lethal phenotypes under the normal culture conditions. The thic1 mutant could be rescued by supplementation of thiamine and its defect functions could be complemented by expression of AtTHIC cDNA. Transient expression analysis revealed that the AtTHIC protein targets plastids and chloroplasts. AtTHIC was strongly expressed in leaves, flowers and siliques and the transcription of AtTHIC was downregulated by extrinsic thiamine. In conclusion, AtTHIC is a gene involved in pyrimidine synthesis in the thiamine biosynthesis pathway of Arabidopsis, and our results provide some new clues for elucidating the pathway of thiamine biosynthesis in plants.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

AtTHIC, a gene involved in thiamine biosynthesis in Arabidopsis thaliana

Kong

Zhu

et al. 2008

Cell Res

View full text Add to dashboard Cite

show abstract

“…Later on, this riboswitch was also discovered in fungi, algae and higher plants. The thiC gene is involved in the production of phosphomethyl pyrimidine synthase enzyme which is the first gene in the operon of ThiCEFSGH in E. coli (Vander Horn et al, 1993) and a separate gene in B. subtilis. This enzyme starts the thiamine biosynthesis pathway with catalyzing the synthesis of the hydroxymethylpyrimidine phosphate (HMP-P) moiety of thiamine from aminoimidazole ribotide (AIR) (Lawhorn et al, 2004).…”

Section: Discussionmentioning

confidence: 99%

“…Thiamine pyrophosphate (TPP) is the active form of vitamin B 1 and an important factor in several metabolic pathways (Vander Horn et al, 1993). The TPP riboswitch is the most widespread riboswitch and was also one of the first riboswitches introduced by Breaker and co-workers in E. coli (Winkler et al, 2002) and Mironov et al in B. subtilis (Mironov et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

TPP riboswitch characterization in Alishewanella tabrizica and Alishewanella aestuarii and comparison with other TPP riboswitches

Aghdam

Sinn

Tarhriz

et al. 2017

Microbiological Research

View full text Add to dashboard Cite

a b s t r a c tRiboswitches are located in non-coding areas of mRNAs and act as sensors of cellular small molecules, regulating gene expression in response to ligand binding. The TPP riboswitch is the most widespread riboswitch occurring in all three domains of life. However, it has been rarely characterized in environmental bacteria other than Escherichia coli and Bacillus subtilis. In this study, TPP riboswitches located in the 5 UTR of thiC operon from Alishewanella tabrizica and Alishewanella aestuarii were identified and characterized. Moreover, affinity analysis of TPP binding to the TPP aptamer domains originated from A. tabrizica, A. aestuarii, E.coli, and B. subtilis were studied and compared using In-line probing and Surface Plasmon Resonance (SPR). TPP binding to the studied RNAs from A. tabrizica and A. aestuarii caused distinctive changes of the In-line cleavage pattern, demonstrating them as functional TPP riboswitches. With dissociation constant of 2-4 nM (depending on the method utilized), the affinity of TPP binding was highest in A. tabrizica, followed by the motifs sourced from A. aestuarii, E. coli, and B. subtilis. The observed variation in their TPP-binding affinity might be associated with adaptation to the different environments of the studied bacteria.

show abstract

“…Bacimethrin is a thiamine antagonist produced by grampositive bacteria, including Streptomyces albus (7) and Bacillus megaterium (29) (Fig. 1).…”

mentioning

confidence: 99%

Action of the Thiamine Antagonist Bacimethrin on Thiamine Biosynthesis

2000

View full text Add to dashboard Cite

Bacimethrin is an analog of the 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP) moiety of thiamine and inhibits the growth of Salmonella enterica serovar Typhimurium on a defined medium. Two classes of mutants that had increased bacimethrin resistance were isolated and characterized. Results showed that overexpression of the thi operon or specific lesions in thiD resulted in a bacimethrin-resistant phenotype. Phenotypic analyses of the thiD mutants suggested that they had a specific defect in one of the two kinase activities associated with this gene product and, further, that ThiD and not PdxK was primarily responsible for salvage of HMP from the medium.Thiamine is synthesized de novo by many bacteria. Although the general outline of the thiamine biosynthetic pathway in enteric microorganisms is known, the individual reactions in this pathway are not yet fully understood. Thiamine pyrophosphate (TPP), the biologically active cofactor, is generated by the condensation of two independently synthesized intermediates, 4-methyl-5-(␤-hydroxyethyl)thiazole (THZ) phosphate and 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP) pyrophosphate. In vivo labeling studies demonstrated that the carbon atoms in HMP were derived from the purine intermediate aminoimidazole ribonucleotide (AIR), although the biochemical details of this conversion have not been elucidated (2). Mutations causing an unconditional requirement for exogenous HMP or thiamine map to a single gene, thiC. In vivo labeling also determined the metabolic precursors to the THZ moiety, and several genes have been implicated in this synthesis (2, 18). Our current understanding of the synthesis and salvage of TPP is presented in Fig. 1.While the low cellular requirement for thiamine has complicated the detailed analysis of its biosynthetic pathway, this characteristic has made thiamine synthesis an attractive model system for dissecting the integration of metabolic pathways (25). Characterization of mutations that perturbed, but did not eliminate, thiamine synthesis has resulted in the identification of a number of loci required for optimal synthesis of this vitamin and has increased our understanding of the integration of thiamine biosynthesis with central cellular processes (1, 5, 6, 8, 10-12, 24b, 25, 27).Use of metabolic inhibitors, or analogs, has provided insight in the studies of a number of metabolic pathways, including histidine (17), folate (3), and branched-chain amino acids (19)(20)(21). Bacimethrin is a thiamine antagonist produced by grampositive bacteria, including Streptomyces albus (7) and Bacillus megaterium (29) (Fig. 1). Previous reports showed that the inhibitory effect of bacimethrin on defined medium could be overcome by exogenous addition of thiamine or the HMP moiety (7).Wild-type Salmonella enterica serovar Typhimurium strain LT2 was unable to grow on solid minimal medium in the presence of 130 nM bacimethrin, and resistant mutants arose spontaneously at a frequency of ϳ10 Ϫ7 (data not shown). Growth of the wild-type strain was restored ...

show abstract

Structural genes for thiamine biosynthetic enzymes (thiCEFGH) in Escherichia coli K-12

Cited by 113 publications

References 39 publications

AtTHIC, a gene involved in thiamine biosynthesis in Arabidopsis thaliana

AtTHIC, a gene involved in thiamine biosynthesis in Arabidopsis thaliana

TPP riboswitch characterization in Alishewanella tabrizica and Alishewanella aestuarii and comparison with other TPP riboswitches

Action of the Thiamine Antagonist Bacimethrin on Thiamine Biosynthesis

Contact Info

Product

Resources

About