Organization of citric acid cycle enzymes into a multienzyme cluster

  title={Organization of citric acid cycle enzymes into a multienzyme cluster},
  author={Sarah J. Barnes and P. David J. Weitzman},
  journal={FEBS Letters},
Citric acid cycle Metabolic organization Bacteria Enzyme association Multienzyme cluster Mitochondria Enzyme organization 
Interaction of enzymes of the tricarboxylic acid cycle in Bacillus subtilis and Escherichia coli: a comparative study
It is found that co-transcription of genes and subsequent co-translation of the corresponding mRNAs promotes the formation of protein complexes and give support for the previous findings that in B. subtilis citrate synthase, isocitrate dehydrogenase and malate dehydrogenases form an enzyme complex (metabolon). Expand
Mitochondrial Citrate Synthase Is Immobilized in Vivo *
Comparison of the 19F NMR resonance intensities from the labeled tricarboxylic acid cycle enzyme in the intact cell and in cell-free lysates indicated that the enzyme is motionally restricted in vivo, consistent with its participation in a multienzyme complex. Expand
The Krebs Citric Acid Cycle
The citric acid cycle (CAC) has several functions in aerobic bacteria and, being a strict aerobe, runs a complete CAC, as is demonstrated by enzyme activity measurements with cell extracts or purified enzymes and by the ability of this bacterium to grow on most of the intermediates of the CAC as sole carbon source. Expand
Regulatory interactions of enzymes of the citric acid cycle in Bacillus subtilis
It is demonstrated that malate-mediated repression is achieved by the global mechanism of CCR via the CcpA/HPrK pathway and that malates triggers the formation of ATP and fructose 1,6-bisphosphate levels sufficient for Ccp a/H PrK pathway activation. Expand
Citric Acid Cycle Regulation: Back Bone for Secondary Metabolite Production
  • Punith Kumar, K. Dubey
  • Chemistry
  • New and Future Developments in Microbial Biotechnology and Bioengineering
  • 2019
Abstract The citric acid cycle (CAC) is recognized as the central hub of a large number of metabolic pathways. It is commonly known as the Krebs cycle or tricarboxylic acid cycle. It starts from theExpand
The visualization by affinity electrophoresis of a specific association between the consecutive citric acid cycle enzymes fumarase and malate dehydrogenase.
Several metabolites (citrate, isocitrate, 2-oxoglutarate, succinate, fumarate, malate, oxaloacetate, Pi, AMP, ADP, NAD+, NADH) were found not to affect the association between fumarase and mitochondrial malate dehydrogenase, but both ATP, Mg2+ -ATP and GTP disrupt the association when they are present at 1 mM concentrations. Expand
Physical interactions between tricarboxylic acid cycle enzymes in Bacillus subtilis: evidence for a metabolon.
A link between the TCA cycle and gluconeogenesis through a flexible interaction of two proteins is discovered: the association between the malate dehydrogenase and phosphoenolpyruvate carboxykinase is directly controlled by the metabolic flux. Expand
Aconitate hydratase of mammals under oxidative stress
The role of aconitate hydratase and structurally similar iron-regulatory protein in maintenance of homeostasis of cell iron and changes in expression under oxidative stress is considered. Expand
Mitochondrial Structure, Function and Biogenesis
Because of their symbiotic origin, mitochondria are often regarded as semiauto-nomous, bacteria-like structures suspended in the cytoplasm. Nevertheless, the structure and distribution ofExpand
citric acid cycle obliges aminolevulinic acid synthesis via the C 5 pathway in a methylotroph
The enzymic activities of the citric acid cycle and the connected pathway of 5-aminolevulinic acid (ALA) formation in the methylotroph Methyfophifus rnethyfotrophus (strain AS1) have been studied.Expand


Unity and diversity in some bacterial citric acid-cycle enzymes.
  • P. Weitzman
  • Chemistry, Medicine
  • Advances in microbial physiology
  • 1981
This chapter explores that the citric acid cycle was accepted as the terminal pathway for the oxidation of foodstuffs in all respiring animal tissues and concentrates heavily on aspects of citrate synthase and succinate thiokinase. Expand
Ambiquitous enzymes: Variation in intracellular distribution as a regulatory mechanism
Several enzymes have been found to reversibly partition between kinetically distinct soluble andmembrane-boundforms, with the distribution between theseforms influenced by specific metabolites,Expand
Unique catalytic properties of enzyme clusters
Evidence is accumulating which suggests that many of the enzymes in cells are organized in some manner, and that at least some of the conceived unique catalytic properties are expressed. Expand
Protein crystals as a model for mitochondrial matrix proteins
Abstract Information on the structure of protein crystals and the activity of crystalline enzymes may be used to help understand the structure of the mitochondrial matrix and the activity of theExpand
Organization of Krebs tricarboxylic acid cycle enzymes in mitochondria.
It is shown that gentle sonic or osmotic disruption can be used to obtain a mitochondrial preparation where these enzymes appear to be organized in a large complex of proteins. Expand
On the role of organized multienzyme systems in cellular metabolism: a general synthesis.
  • G. R. Welch
  • Physics, Medicine
  • Progress in biophysics and molecular biology
  • 1977
Throughout this article, vector quantities are denoted by use of bold type face (e.g. Ai, ri). The symbol ▿ denotes the “gradient” operator and δ(r−r′) the three-dimensional Dirac delta function (seeExpand
The infrastructure of the mitochondrial matrix
Abstract The concentration of the enzymes in the matrix of rat-liver mitochondria is over 50% by weight and they probably exist and behave as a multienzyme complex rather than as enzymes in solution.Expand
Demonstration of physical interactions between consecutive enzymes of the citric acid cycle and of the aspartate-malate shuttle. A study involving fumarase, malate dehydrogenase, citrate synthesis and aspartate aminotransferase.
It is proposed that these enzymes bind alternatively, in order to allow the cell to perform citric acid cycle or shuttle reactions, according to its needs, which is consistent with a model in which maximally four molecules of malate dehydrogenase are bound to one fumarase molecule. Expand
Interaction between citrate synthase and mitochondrial malate dehydrogenase in the presence of polyethylene glycol.
Pig heart citrate synthase and mitochondrial malate dehydrogenase interact in polyethylene glycol solutions as indicated by increased solution turbidity, and the observed interaction is highly specific in that neither cytosolic malate dehydration nor nine other proteins showed evidence of specific interaction with either pig heart citrates synthase or mitochondrialmalate dehydration. Expand
A study on the physical interaction between the pyruvate dehydrogenase complex and citrate synthase.
Experiments with active enzyme gel chromatography indicate that citrate synthase also associates with pyruvate dehydrogenase complex in its functioning state, raising the possibility of the dynamic compartmentation of acetyl-CoA in the mitochondria which results in the direction of acetylene from pyruVate towards citrate. Expand