A chicken liver cDNA for 6-phosphofructo-2-kinase/fructose-2,6. bisphosphatase was isolated from a Lambda ZAP2 phage library. The chicken liver cDNA codes for a protein that has 89.1, 88.4 and 88.0% amino acid identity with the human, rat and bovine liver isoforms, respectively. The kinetic properties of the rat and chicken liver enzymes, purified to homogeneity after expression in E. coli, were different including negative cooperativity for ATP binding and inhibition by Mg2+ for the chicken liver 6-phosphofructo-2-kinase but not for the rat liver kinase. Differences in the β-loop ATP signature sequences in the chicken and rat liver kinase domains may explain the kinetic differences and represent the major divergence in the evolution of the enzyme from birds to mammals.
|Original language||English (US)|
|Number of pages||9|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Jan 29 1993|