A novel enzyme, citryl‐CoA lyase, catalysing the second step of the citrate cleavage reaction in Hydrogenobacter thermophilus TK‐6

  title={A novel enzyme, citryl‐CoA lyase, catalysing the second step of the citrate cleavage reaction in Hydrogenobacter thermophilus TK‐6},
  author={Miho Aoshima and Masaharu Ishii and Yasuo Igarashi},
  journal={Molecular Microbiology},
A novel enzyme catalysing citryl‐CoA cleavage to acetyl‐CoA and oxaloacetate was purified from Hydrogenobacter thermophilus TK‐6, and designated citryl‐CoA lyase (CCL). The citrate cleavage reaction in this organism proceeded by a unique set of two consecutive reactions: (i) citryl‐CoA formation by citryl‐CoA synthetase (CCS) and (ii) citryl‐CoA cleavage by CCL. Purified CCL gave a single 30 kDa band in SDS–PAGE and gel filtration chromatography indicated that the native state of the enzyme… 
A novel oxalosuccinate‐forming enzyme involved in the reductive carboxylation of 2‐oxoglutarate in Hydrogenobacter thermophilus TK‐6
CFI was confirmed to be a novel enzyme that catalyses the car boxylation of 2‐oxoglutarate to form oxalosuccinate, which corresponds to the first step of the reductive carboxylation from 2‐ oxoglutamate to isocitrate.
Properties of R-Citramalyl-Coenzyme A Lyase and Its Role in the Autotrophic 3-Hydroxypropionate Cycle of Chloroflexus aurantiacus
Genes similar to those involved in CO(2) fixation in C. aurantiacus, including an R-citramalyl-CoA lyase gene, were found in Roseiflexus sp.
Structure of ATP citrate lyase and the origin of citrate synthase in the Krebs cycle.
Crystal structures of ATP citrate lyase from bacteria, archaea and humans unravel how the enzyme directs the formation of the central metabolite acetyl-CoA, and shed light onto the evolutionary origins of the Krebs cycle.
Autotrophic CO2 fixation via the reductive tricarboxylic acid cycle in different lineages within the phylum Aquificae: evidence for two ways of citrate cleavage.
Findings substantiate the hypothesis that autotrophic carbon fixation through the reductive TCA cycle is widespread and contributes significantly to biomass production particularly in hydrothermal habitats.
Carboxylation reaction catalyzed by 2-oxoglutarate:ferredoxin oxidoreductases from Hydrogenobacter thermophilus
This is the first reported kinetic analysis of carbon fixation catalyzed by OGOR enzymes from the rTCA cycle and both the apparent maximum velocities and the Km values of For and Kor for the carboxylation of succinyl-CoA are determined.
Reversibility of citrate synthase allows autotrophic growth of a thermophilic bacterium
The sulfur-reducing anaerobic deltaproteobacterium Desulfurella acetivorans is capable of both acetate oxidation and autotrophic carbon fixation, with the tricarboxylic acid cycle operating either in the oxidative or reductive direction, respectively.
Novel enzyme reactions related to the tricarboxylic acid cycle: phylogenetic/functional implications and biotechnological applications
  • M. Aoshima
  • Biology, Engineering
    Applied Microbiology and Biotechnology
  • 2007
The tricarboxylic acid (TCA) cycle is an energy-producing pathway for aerobic organisms. However, it is widely accepted that the phylogenetic origin of the TCA cycle is the reductive TCA cycle, which
Two Tandemly Arranged Ferredoxin Genes in the Hydrogenobacter thermophilus Genome: Comparative Characterization of the Recombinant [4Fe–4S] Ferredoxins
Spectroscopic analyses of the purified recombinant ferredoxins heterologously expressed in Escherichia coli indicated that each ferredoxin contains a single [4Fe–4S]2+⁄1+ cluster.
Biochemical elucidation of citrate accumulation in Synechocystis sp. PCC 6803 via kinetic analysis of aconitase
A unicellular cyanobacterium Synechocystis sp. PCC 6803 possesses a unique tricarboxylic acid (TCA) cycle, wherein the intracellular citrate levels are approximately 1.5–10 times higher than the
A primordial and reversible TCA cycle in a facultatively chemolithoautotrophic thermophile
Phylometabolic evaluation suggests that the TCA cycle with reversible CS may represent an ancestral mode of the rTCA cycle and raises the possibility of a facultatively chemolithomixotrophic origin of life.


A novel enzyme, citryl‐CoA synthetase, catalysing the first step of the citrate cleavage reaction in Hydrogenobacter thermophilus TK‐6
A novel citrate cleavage pathway, which does not involve ACL, appears to exist in this organism, and the evolutionary relationship between CCS, SCS and ACL is discussed.
ATP-citrate lyase from the green sulfur bacterium Chlorobium limicola is a heteromeric enzyme composed of two distinct gene products.
This paper provides the first direct evidence that a bacterial ATP-citrate lyase is a heteromeric enzyme, distinct from mammalian enzymes.
A novel biotin protein required for reductive carboxylation of 2‐oxoglutarate by isocitrate dehydrogenase in Hydrogenobacter thermophilus TK‐6
Observations indicate that the novel biotin protein is an ATP‐dependent factor, which is involved in the reverse (carboxylating) reaction of isocitrate dehydrogenase, which was purified from Hydrogenobacter thermophilus.
Purification and characterization of ATP:citrate lyase from Hydrogenobacter thermophilus TK-6
The enzyme was quite stable, even in the absence of sulfhydryl reagents, and showed citrate synthase activity in the presence of Mg2+, but the reaction rate was very low (less than 1/200 of the lyase activity).
Acetyl-CoA-dependent cleavage of citrate on inactivated citrate lyase.
It was concluded that phosphopantetheine most likely represents the acyl-carrying group in this complex, and citrate lyase was characterized as a multienzyme complex.
Catalytic strategy of citrate synthase: subunit interactions revealed as a consequence of a single amino acid change in the oxaloacetate binding site.
The effects on the catalytic mechanism of changing this important residue to glycine in pig heart citrate synthase are reported, leading to the conclusion that the mutant less readily undergoes a conformation change required for efficient activation of substrates.
The CO2 assimilation via the reductive tricarboxylic acid cycle in an obligately autotrophic, aerobic hydrogen-oxidizing bacterium, Hydrogenobacter thermophilus
Findings strongly suggested that a new type of the reductive tricarboxylic acid cycle operated as the CO2 fixation pathway in Hydrogenobacter thermophilus.
Enzymes of the reductive citric acid cycle in the autotrophic eubacterium Aquifex pyrophilus and in the archaebacterium Thermoproteus neutrophilus
The reductive citric acid cycle for autotrophic CO2 fixation now has been documented in the eubacterial branches of the proteobacteria, in green sulfur bacteria, and in the thermophilic Knallgas bacteria as well as in the branch of the sulfur dependent archaebacteria.
ADP-binding site of Escherichia coli succinyl-CoA synthetase revealed by x-ray crystallography.
The specific interactions of the nucleotide-Mg(2+) complex with SCS are described, compared with those for other proteins containing the ATP-grasp fold, and a hypothetical model of the histidine-containing loop in the "down" position is presented.