Quo vadis photorespiration: a tale of two aldolases.
An O2-consuming side reaction of D-ribulose 1,5-bisphosphate carboxylase causes photorespiration in plants. This reaction may be an inevitable consequence of the enzyme's inability to protect its ene-diolate reaction intermediate from O2, a notion that is supported by the failure of persistent efforts to eliminate selectively its oxygenase activity by genetic manipulation. We have examined two a1dolases with similar ene-diolate intermediates, L-rhamnulose 1-phosphate aldolase and L-fuculose 1-phosphate aldolase. The former enzyme has an oxygenase activity, while the latter does not, suggesting that the reaction with O2 is not inevitable.
Hixon
M
M
Department of Medicinal Chemistry, University of Kansas, Lawrence 66045, USA.
Sinerius
G
G
Schneider
A
A
Walter
C
C
Fessner
W D
WD
Schloss
J V
JV
D000446:Aldehyde-Lyases / Q000378:metabolism*; D019069:Cell Respiration; D004926:Escherichia coli / Q000201:enzymology; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D008670:Metals / Q000378:metabolism; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*
D008670:Metals; D006861:Hydrogen Peroxide; D000446:Aldehyde-Lyases; D005634:Fructose-Bisphosphate Aldolase; C036027:L-fuculosephosphate aldolase; C022526:rhamnulose-1-phosphate adolase; D010100:Oxygen