Thermotoga maritima phosphofructokinases: expression and characterization of two unique enzymes.
A pyrophosphate-dependent phosphofructokinase (PP(i)-PFK) and an ATP-dependent phosphofructokinase (ATP-PFK) from Thermotoga maritima have been cloned and characterized. The PP(i)-PFK is unique in that the K(m) and V(max) values indicate that polyphosphate is the preferred substrate over pyrophosphate; the enzyme in reality is a polyphosphate-dependent PFK. The ATP-PFK was not significantly affected by common allosteric effectors (e.g., phosphoenolpyruvate) but was strongly inhibited by PP(i) and polyphosphate. The results suggest that the control of the Embden-Meyerhof pathway in this organism is likely to be modulated by pyrophosphate and/or polyphosphate.
Ding
Y R
YR
Thermophile Research Unit, Department of Biological Sciences, The University of Waikato, Hamilton, New Zealand.
Ronimus
R S
RS
Morgan
H W
HW
D000255:Adenosine Triphosphate / Q000378:metabolism; D000494:Allosteric Regulation; D011756:Diphosphates / Q000378:metabolism; D005636:Fructosephosphates / Q000378:metabolism; D010732:Phosphofructokinase-1 / Q000235:genetics / Q000378:metabolism*; D010770:Phosphotransferases / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D020124:Thermotoga maritima / Q000201:enzymology*
D011756:Diphosphates; D005636:Fructosephosphates; D011994:Recombinant Proteins; C027618:fructose-6-phosphate; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; D010732:Phosphofructokinase-1; C022502:pyrophosphate-fructose 6-phosphate 1-phosphotransferase