Analyses of enzyme II gene mutants for sugar transport and heterologous expression of fructokinase gene in Corynebacterium glutamicum ATCC 13032.
Corynebacterium glutamicum ATCC 13032 has four enzyme II (EII) genes of the phosphotransferase system in its genome encoding transporters for sucrose, glucose, fructose, and an unidentified EII. To analyze the function of these EII genes, they were inactivated via homologous recombination and the resulting mutants characterized for sugar utilization. Whereas the sucrose EII was the only transport system for sucrose in C. glutamicum, fructose and glucose were each transported by a second transporter in addition to their corresponding EII. In addition, the ptsF ptsG double mutant carrying deletions in the EII genes for fructose and glucose accumulated fructose in the culture broth when growing on sucrose. As no fructokinase gene exists in the C. glutamicum genome, the fructokinase gene from Clostridium acetobutylicum was expressed in C. glutamicum and resulted in the direct phosphorylation of fructose without any fructose efflux. Accordingly, since fructokinase could direct fructose flux to the pentose phosphate pathway for the supply of NADPH, fructokinase expression may be a potential strategy for enhancing amino acid production.
Moon
Min-Woo
MW
Laboratory of Microbial Genomics, Korea Research Institute of Bioscience and Biotechnology, Daejon 305-600, Korea.
Kim
Hyo-Jin
HJ
Oh
Tae-Kwang
TK
Shin
Chul-Soo
CS
Lee
Jong-Soo
JS
Kim
Seong-Jun
SJ
Lee
Jung-Kee
JK
D048230:Corynebacterium glutamicum / Q000235:genetics* / Q000378:metabolism; D005631:Fructokinases / Q000235:genetics / Q000378:metabolism*; D005632:Fructose / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism*; D009154:Mutation; D010427:Pentose Phosphate Pathway / Q000502:physiology
D005632:Fructose; D005631:Fructokinases; D005947:Glucose