High impact information on FBP26

• Evolution of a bifunctional enzyme: 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase [1].
• Structure, function, and evolution of phosphoglycerate mutases: comparison with fructose-2,6-bisphosphatase, acid phosphatase, and alkaline phosphatase [2].
• The complete amino acid sequence of 6-phospho-fructo-2-kinase/fructose-2,6-bisphosphatase from rat liver was determined by direct analysis of the S-carboxamidomethyl protein [3].
• The catalytic-site histidine residues are no longer in a "clapping-hands" conformation, but more resemble the conformation seen in the distantly related enzymes prostatic acid phosphatase and fructose-2,6-bisphosphatase [4].
• Therefore the natural mutation of Lys-174 to glycine in the fbp26 yeast isoenzyme could explain the lack of 6-phosphofructo-2-kinase activity [5].

Biological context of FBP26

• The deduced amino acid sequence has 42% identity with the 55-kDa subunit of the bifunctional 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase from rat liver with extra material at both ends [6].
• The bifunctional rat liver enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (ATP:D-fructose-6-phosphate 2-phosphotransferase/D-fructose-2,6-bisphosphate 2-phosphohydrolase, EC 2.7.1.105/EC 3.1.3.46) is constructed of two independent catalytic domains [1].
• We have isolated cDNA clones encoding the regulatory enzyme fructose-6-phosphate,2-kinase/fructose-2,6-bisphosphatase from a potato (Solanum tuberosum) leaf cDNA library [7].

Associations of FBP26 with chemical compounds

• The product of the new yeast gene is similar to the entire sequence of the bifunctional rat liver enzyme and, unlike yeast 6-phosphofructo-2-kinase, has the histidine residue essential for fructose-2,6-bisphosphatase activity [8].
• The newly created fructose-2,6-bisphosphatase is inhibited competitively by its product fructose 6-P with a K(i) of 0.6 mM [9].
• Regulation of rat 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase. Role of the NH2-terminal region [10].
• The corresponding residues in rat liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase, Arg-257 and Arg-307, were mutated to alanine [11].
• Arg-257 and Arg-307 of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase bind the C-2 phospho group of fructose-2,6-bisphosphate in the fructose-2,6-bisphosphatase domain [11].

Regulatory relationships of FBP26

• This effect was partially suppressed by overexpressing constitutively active 6-phosphofructo-2-kinase (Pfk26(Asp644)) or by inactivating fructose-2,6-bisphosphatase (in a Deltafbp26 mutant) [12].

Other interactions of FBP26

• Remarkably, and in deep contrast to what is known of mammalian and plant enzymes, phosphofructokinase 2 and the low-Km fructose-2,6-bisphosphatase clearly separated from each other in all purification procedures used [13].

Analytical, diagnostic and therapeutic context of FBP26

• Site-directed mutagenesis of Lys-174, Asp-179 and Asp-191 in the 2-kinase domain of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase [5].

References