Evolution of enzymatic activities in the enolase superfamily: characterization of the (D)-glucarate/galactarate catabolic pathway in Escherichia coli.
The genes encoding the enzymes in the (D)-glucarate/galactarate catabolic pathway have been identified in the Escherichia coli genome. These encode, in three transcriptional units, (D)-glucarate dehydratase (GlucD), galactarate dehydratase, 5-keto-4-deoxy-(D)-glucarate aldolase, tartronate semialdehyde reductase, a glycerate kinase that generates 2-phosphoglycerate as product, and two hexaric acid transporters. We also have identified a gene proximal to that encoding GlucD that encodes a protein that is 72% identical in primary sequence to GlucD (GlucD-related protein or GlucDRP). However, whereas GlucD catalyzes the efficient dehydration of both (D)-glucarate and (L)-idarate as well as their epimerization, GlucDRP is significantly impaired in both reactions. Perhaps GlucDRP is an example of gene duplication and evolution in progress in the E. coli chromosome.
Hubbard
B K
BK
Department of Biochemistry, University of Illinois at Urbana-Champaign 61801, USA.
Koch
M
M
Palmer
D R
DR
Babbitt
P C
PC
Gerlt
J A
JA
D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000235:genetics; D000446:Aldehyde-Lyases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D000595:Amino Acid Sequence; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D019143:Evolution, Molecular; D005937:Glucaric Acid / Q000737:chemistry* / Q000378:metabolism; D006836:Hydro-Lyases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009876:Operon; D010751:Phosphopyruvate Hydratase / Q000737:chemistry*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013400:Sugar Acids / Q000737:chemistry* / Q000378:metabolism
D029968:Escherichia coli Proteins; D013400:Sugar Acids; C000090:galactaric acid; D000429:Alcohol Oxidoreductases; C064167:2-hydroxy-3-oxopropionate reductase; D017853:Phosphotransferases (Alcohol Group Acceptor); C020670:glycerate kinase; D000446:Aldehyde-Lyases; C021468:2-keto-3-deoxy-D-glucarate aldolase; D006836:Hydro-Lyases; C115104:garD protein, E coli; C115105:gudX protein, E coli; D010751:Phosphopyruvate Hydratase; C020572:glucarate dehydratase; D005937:Glucaric Acid