Home About us Contact
|
Home About us Contact | ||
|
|
||
Pyruvate Formate Lyase (pyruvate + formate_lyase)
Selected AbstractsPyruvate Formate Lyase (PFL) and PFL Activating Enzyme in the Chytrid Fungus Neocallimastix frontalis: A Free-Radical Enzyme System Conserved Across Divergent Eukaryotic Lineages,THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 4 2004GABRIEL GELIUS-DIETRICH ABSTRACT Fermentative formate production involves the activity of pyruvate formate lyase, an oxygen-sensitive enzyme that employs a glycyl radical in its reaction mechanism. While common among anaerobic prokaryotes, this enzyme has so far been found in only two distantly related eukaryotic lineages, anaerobic chytridiomycetes and chlorophytes. Sequence comparisons of homologues from the chytridiomycetes Piromyces and Neocallimastix, the chlorophyte Chlamydomonas, and numerous prokaryotes suggest a single, eubacterial origin of eukaryotic pyruvate formate lyases. Pyruvate formate lyase activating enzyme introduces the glycyl radical into the pyruvate formate lyase protein chain. We discovered this enzyme, which had not previously been reported from eukaryotes, in the same two eukaryotic lineages and show that it shares a similar evolutionary history to pyruvate formate lyase. Sequences with high homology to pyruvate formate lyase activating enzyme were identified in the genomes of the anaerobic protozoan parasites Trichomonas vaginalis, Entamoeba histolytica, and Giardia intestinalis. While the occurrence of pyruvate formate lyase activating enzyme together with pyruvate formate lyase in fungi and chlorophytes was to be expected, the target protein of a glycyl radical enzyme-activating enzyme in these protozoa remains to be identified. [source] Doubling the catabolic reducing power (NADH) output of Escherichia coli fermentation for production of reduced productsBIOTECHNOLOGY PROGRESS, Issue 1 2010Shengde Zhou Abstract Homofermentative production of reduced products requires additional reducing power output (NADH) from glucose catabolism. Anaerobic expression of the pyruvate dehydrogenase complex (PDH, encoded by aceEF-lpd, a normal aerobic operon) is able to provide the additional NADH required for production of reduced products in Escherichia coli fermentation. The multiple promoters (pflBp(1,7)) of pyruvate formate lyase (pflB) were evaluated for anaerobic expression of the aceEF-lpd operon. Four chromosomal constructs, pflBp(1,7)-aceEF-lpd, pflBp(1,6)-aceEF-lpd, pflBp(6,7)-aceEF-lpd, and pflBp6-aceEF-lpd efficiently expressed the PDH complex in anaerobically grown cells. Doubling the reducing power output was achieved when glucose was oxidized to acetyl-CoA through glycolysis and pyruvate oxidation by the anaerobically expressed PDH complex (glucose ,2 acetyl-CoA + 4 NADH). This additional reducing power output can be used for production of reduced products in anaerobic E. coli fermentation. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Pyruvate Formate Lyase (PFL) and PFL Activating Enzyme in the Chytrid Fungus Neocallimastix frontalis: A Free-Radical Enzyme System Conserved Across Divergent Eukaryotic Lineages,THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 4 2004GABRIEL GELIUS-DIETRICH ABSTRACT Fermentative formate production involves the activity of pyruvate formate lyase, an oxygen-sensitive enzyme that employs a glycyl radical in its reaction mechanism. While common among anaerobic prokaryotes, this enzyme has so far been found in only two distantly related eukaryotic lineages, anaerobic chytridiomycetes and chlorophytes. Sequence comparisons of homologues from the chytridiomycetes Piromyces and Neocallimastix, the chlorophyte Chlamydomonas, and numerous prokaryotes suggest a single, eubacterial origin of eukaryotic pyruvate formate lyases. Pyruvate formate lyase activating enzyme introduces the glycyl radical into the pyruvate formate lyase protein chain. We discovered this enzyme, which had not previously been reported from eukaryotes, in the same two eukaryotic lineages and show that it shares a similar evolutionary history to pyruvate formate lyase. Sequences with high homology to pyruvate formate lyase activating enzyme were identified in the genomes of the anaerobic protozoan parasites Trichomonas vaginalis, Entamoeba histolytica, and Giardia intestinalis. While the occurrence of pyruvate formate lyase activating enzyme together with pyruvate formate lyase in fungi and chlorophytes was to be expected, the target protein of a glycyl radical enzyme-activating enzyme in these protozoa remains to be identified. [source] | ||||||||||