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Phosphofructokinase I
7.Transferring phosphorus-containing groups
1.Phosphotransferases with an alcohol group as acceptor
ADP
+ D-fructose 1,6-bi-PUTP
CTP
ITP
D-fructose 6-P
D-Tagatose 6-P
Sedoheptulose 7-P
UDP
CDP
IDP
D-fructose 1,6-bi-P
D-Tagatose 1,6-bi-P
Sedoheptulose 1,7-bi-P
GDP
phosphoenolpyruvate
D-tagatose 6-phosphate and sedoheptulose 7-phosphate can act as acceptors. UTP, CTP and ITP can act as donors.
Phosphofructokinase is a key regulatory enzyme in
the glycolytic pathway. It catalyzes the phosphorylation by ATP of fructose
6-phosphate to fructose 1,6-bisphosphate. In bacteria PFK is a tetramer of
identical 36 Kd subunits. In mammals it is a tetramer of 80 Kd subunits. Each
80 Kd subunit consist of two homologous domains which are highly related to
the bacterial 36 Kd subunits. In Human there are three, tissue-specific, types
of PFK isozymes: PFKM (muscle), PFKL (liver), and PFKP (platelet). In yeast
PFK is an octamer composed of four 100 Kd alpha chains (gene PFK1) and four
100 Kd beta chains (gene PFK2); like the mammalian 80 Kd subunits, the yeast
100 Kd subunits are composed of two homologous domains.
As a signature pattern for PFK it has been selected a region that contains three basic
residues involved in fructose-6-phosphate binding.
Reference