Open AccessKetohexokinase (ATP: d ‐fructose 1‐phosphotransferase) initiates fructose breakdown via the modified EMP pathway in halophilic archaebacteria
Author(s) -
Altekar Wijaya,
Rangaswamy Vidhya
Publication year - 1991
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1991.tb04471.x
Subject(s) - aldolase b , aldolase a , dihydroxyacetone phosphate , fructose bisphosphate aldolase , fructose , biochemistry , phosphotransferase , glyceraldehyde , biology , pep group translocation , glycolysis , fructolysis , fructose 1,6 bisphosphatase , enzyme , chemistry , dehydrogenase , phosphoenolpyruvate carboxykinase
Ketohexokinase, catalysing the ATP‐dependent phosphorylation of d ‐fructose to fructose 1‐phosphate was identified as the enzyme responsible for the initiation of fructose breakdown via the modified EMP pathway in the halophilic arachaebacterium Haloarchla vallismortis . The phosphorylated product was identified as fructose 1‐phosphate through its conversion to (i) a biphosphate ester by H. vallismortis 1‐phosphofruktokinase, and (ii) trioses by rabbit muscle aldolase. The product of ketohexokinase reaction gave glyceraldehyde and dihydroxyacetone phosphate when cleaved directly by mammalian muscle aldolase, whereas, glyceraldehyde 3‐phosphate and dihydroxyacetone phosphate were produced when it was converted to the biphosphate ester prior to the treatment with aldolase. This is a first demonstration of ketohexokinase not only in an arachaebacterium but also in a prokaryote.