The role of xylulokinase in Saccharomyces cerevisiae xylulose catabolism.
Many yeast species have growth rates on D-xylulose of 25-130% of those on glucose, but for Saccharomyces cerevisiae this ratio is only about 6%. The xylulokinase reaction has been proposed to be the rate-limiting step in the D-xylulose fermentation with S. cerevisiae. Over-expression of xylulokinase encoding XKS1 stimulated growth on D-xylulose in a S. cerevisiae strain to about 20% of the growth rate on glucose and deletion of the gene prevented growth on D-xylulose and D-xylulose metabolism. We have partially purified the xylulokinase and characterised its kinetic properties. It is reversible and will also accept D-ribulose as a substrate.
Richard
P
P
VTT Biotechnology, Espoo, Finland. peter.richard@vtt.fi
Toivari
M H
MH
Penttilä
M
M
D005285:Fermentation; D017353:Gene Deletion; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D010429:Pentoses / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D014996:Xylulose / Q000378:metabolism*
D010429:Pentoses; C100182:ribulose; D014996:Xylulose; D017853:Phosphotransferases (Alcohol Group Acceptor); C032700:xylulokinase; D005947:Glucose