Disease relevance of pta

• The pta gene encoding phosphotransacetylase was cloned on a high copy plasmid with or without the ackA gene encoding acetate kinase in Escherichia coli [1].
• Catabolite regulation of the pta gene as part of carbon flow pathways in Bacillus subtilis [2].
• The defective growth and starvation survival of the pta mutant were restored by the introduction of poly-beta-hydroxybutyrate (PHB) synthesis genes (phbCAB) from Alcaligenes eutrophus, indicating that the growth defect of the pta mutant was due to a perturbation of acetyl coenzyme A (CoA) flux [3].
• Furthermore, the inhibition effect was more pronounced in glucose minimal medium, whereas the menadione sensitivity was not observed when a gluconeogenic carbon source was used as a sole carbon source or the lactate dehydrogenase gene from Lactobacillus casei was introduced in the pta(-) mutant [4].

High impact information on pta

• In Escherichia coli, acetyl phosphate can be formed from acetyl-CoA via the phosphotransacetylase (phosphate acetyltransferase; acetyl-CoA:orthophosphate acetyltransferase, EC 2.3.1.8) reaction and from acetate (plus ATP) via the acetate kinase (ATP:acetate phosphotransferase, EC 2.7.2.1) reaction [5].
• Here, we demonstrate increased in vivo half-lives of sigma(S) and the RpoS742::LacZ hybrid protein (also a substrate for RssB-dependent proteolysis) in acetyl phosphate-free (pta-ackA) deletion mutants, even though no sensor kinase was eliminated [6].
• Relative to increasing culture density, acetyl-CoA levels and expression from both the pta and ackA promoters decreased [7].
• Several pta mutant strains were examined, and a pta mutant of E. coli RR1 which was deficient in the phosphotransacetylase of the Pta-AckA pathway was found to metabolize glucose to D-lactate and to produce a small amount of succinate by-product under anaerobic conditions [8].
• The pta mutant was found to grow slowly on glucose, TB, or pyruvate, but it grew normally on glycerol or succinate [3].

Chemical compound and disease context of pta

• The porin composition of the Escherichia coli cell envelope was analyzed during growth at different external pHs (pHo) as a function of the acetyl phosphate (AcP) level (DeltaackA pta or ackA mutant, pyruvate or glucose as the carbon source) in the presence or absence of EnvZ [9].
• Although the bacterium E. coli is chosen as the host in many bioprocesses, products derived from the central aerobic metabolic pathway often compete with the acetate-producing pathways poxB and ackA-pta for glucose as the substrate [10].
• A recombinant E. coli strain with a deletion in ackA-pta produces less acetate and more isoamyl acetate than the wild-type E. coli strain [10].
• Acetate metabolism in a pta mutant of Escherichia coli W3110: importance of maintaining acetyl coenzyme A flux for growth and survival [3].
• These results suggest that E. coli excretes acetate due to the pyruvate flux from PTS and that any method which alleviates the oversupply of acetyl CoA would restore normal growth to the pta mutant [3].

Biological context of pta

• A 3,700 nucleotide transcript, which covers the ackA and pta genes, seemed to be produced by the first promoter in the operon and a 2,300 nucleotide transcript, which covers just pta, seemed to be produced by the second promoter [1].
• Nucleotide sequencing of the pta gene revealed that it is able to produce a polypeptide comprising 714 amino acid residues, which starts at 70 base pairs downstream from the stop codon of the ackA gene [1].
• PTasRNAs targeted against the ackA gene within the acetate kinase-phosphotransacetylase operon (ackA-pta) triggered target mRNA decay and a 78% reduction in AckA activity with high genetic penetrance [11].
• Footprinting experiments demonstrated an interaction between CcpA and the pta CRE sequence, which is almost identical to the proposed CRE consensus sequence [2].
• The effects of the predicted cis-acting catabolite response element (CRE) located upstream from the promoter and of the trans-acting proteins CcpA, HPr, Crh, and HPr kinase on the catabolite regulation of pta were investigated [2].

Associations of pta with chemical compounds

• Some of the pta mutants and all of the facA mutants failed to grow on media containing fumarate as terminal electron acceptor or anaerobically on glucose minimal medium [12].
• Inactivation of pta-ackA in NDH-I- or NDH-II-deficient strains lead to increased D-lactate formation and decreased ethanol formation [13].
• The ackA-pta mutant has a pfl::lacZ expression level much higher than that of the wild-type strain, and cultures also exhibit the highest ethanol production [14].
• This observation along with the observed excretion of pyruvate in the ackA-pta strain indicates the significance of intracellular pyruvate pools [15].
• Unlike wild-type strains, such adh pta double mutants were unable to grow anaerobically on sorbitol or on glucuronic acid [16].

Other interactions of pta

• Some of these appeared to be in the pta gene, which encodes phosphotransacetylase, suggesting the possible involvement of acetyl phosphate in ldhA regulation [17].
• Redistribution of metabolic fluxes in the central aerobic metabolic pathway of E. coli mutant strains with deletion of the ackA-pta and poxB pathways for the synthesis of isoamyl acetate [10].
• Analysis of the DNA sequence suggests that the naox and lplA genes are part of a single operon, odpA and odpB constitute an additional operon, odp2 and dldH a third operon, and pta and ack an additional transcription unit [18].
• The GlnAP2 element has been proved to be an effective and inducible-by exogenous acetate-promoter in Escherichia coli with glnL/pta double mutations [19].
• Additional studies of deletions in the menBCD area revealed that this cluster lies between ack/pta and glpT, as in E. coli [20].

References