Open AccessEimeria tenella contains a pyrophosphate‐dependent phosphofructokinase and a pyruvate kinase with unusual allosteric regulators
Author(s) -
Denton Helen,
Thong KamWah,
Coombs Graham H.
Publication year - 1994
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.1574-6968.1994.tb06619.x
Subject(s) - phosphofructokinase , pyruvate kinase , allosteric regulation , phosphoenolpyruvate carboxykinase , biochemistry , biology , glycolysis , kinase , phosphotransferase , pyrophosphate , pep group translocation , phosphofructokinase 2 , fructose , microbiology and biotechnology , enzyme
Sporozoites and unsporulated oocysts of Eimeria tenella were shown to contain a pyrophosphate‐dependent phosphofructokinase (PP i ‐PFK) but apparently lack an ATP‐specific activity. The PP i ‐PFK resembles those that occur in a number of other protists in being reversible and not subject to metabolic control. In contrast, the ADP‐utilising pyruvate kinase, present in two developmental stages of the parasite, exhibited strong positive cooperativity with respect to its substrate, phosphoenolpyruvate, and was shown to be allostetically activated by glucose 6‐phosphate, fructose 6‐phosphate and AMP. It is suggested that the PP i ‐PFK represents an adaptation of the parasite towards life in an environment containing only low concentrations of oxygen and that the unusual allosteric regulation of pyruvate kinase evolved to compensate for glycolysis not being controlled at the PP i ‐PFK step.