Re-citrate synthase from Clostridium kluyveri is phylogenetically related to homocitrate synthase and isopropylmalate synthase rather than to Si-citrate synthase.
The synthesis of citrate from acetyl-coenzyme A and oxaloacetate is catalyzed in most organisms by a Si-citrate synthase, which is Si-face stereospecific with respect to C-2 of oxaloacetate. However, in Clostridium kluyveri and some other strictly anaerobic bacteria, the reaction is catalyzed by a Re-citrate synthase, whose primary structure has remained elusive. We report here that Re-citrate synthase from C. kluyveri is the product of a gene predicted to encode isopropylmalate synthase. C. kluyveri is also shown to contain a gene for Si-citrate synthase, which explains why cell extracts of the organism always exhibit some Si-citrate synthase activity.
Li
Fuli
F
Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse, D-35043 Marburg, Germany.
Hagemeier
Christoph H
CH
Seedorf
Henning
H
Gottschalk
Gerhard
G
Thauer
Rudolf K
RK
D015079:2-Isopropylmalate Synthase / Q000235:genetics* / Q000378:metabolism; D002950:Citrate (si)-Synthase / Q000235:genetics* / Q000378:metabolism; D002951:Citrates / Q000737:chemistry / Q000378:metabolism; D047010:Clostridium kluyveri / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D016680:Genome, Bacterial; D015394:Molecular Structure; D062907:Oxaloacetic Acid / Q000737:chemistry / Q000378:metabolism; D007652:Oxo-Acid-Lyases / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D013237:Stereoisomerism
D002951:Citrates; D062907:Oxaloacetic Acid; D002950:Citrate (si)-Synthase; D015079:2-Isopropylmalate Synthase; C021365:homocitrate synthase; D007652:Oxo-Acid-Lyases