The first crystal structure of phosphofructokinase from a eukaryote: Trypanosoma brucei.
The crystal structure of the ATP-dependent phosphofructokinase (PFK) from Trypanosoma brucei provides the first detailed description of a eukaryotic PFK, and enables comparisons to be made with the crystal structures of bacterial ATP-dependent and PPi-dependent PFKs. The structure reveals that two insertions (the 17-20 and 329-348 loops) that are characteristic of trypanosomatid PFKs, but absent from bacterial and mammalian ATP-dependent PFKs, are located within and adjacent to the active site, and are in positions to play important roles in the enzyme's mechanism. The 90 residue N-terminal extension forms a novel domain that includes an "embracing arm" across the subunit boundary to the symmetry-related subunit in the tetrameric enzyme. Comparisons with the PPi-dependent PFK from Borrelia burgdorferi show that several features thought to be characteristic of PPi-dependent PFKs are present in the trypanosome ATP-dependent PFK. These two enzymes are generally more similar to each other than to the bacterial or mammalian ATP-dependent PFKs. However, there are critical differences at the active site of PPi-dependent PFKs that are sufficient to prevent the binding of ATP. This crystal structure of a eukaryotic PFK has enabled us to propose a detailed model of human muscle PFK that shows active site and other differences that offer opportunities for structure-based drug discovery for the treatment of sleeping sickness and other diseases caused by the trypanosomatid family of protozoan parasites.
Martinez-Oyanedel
José
J
Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Edinburgh EH9 3JR, Scotland.
McNae
Iain W
IW
Nowicki
Matthew W
MW
Keillor
Jeffrey W
JW
Michels
Paul A M
PA
Fothergill-Gilmore
Linda A
LA
Walkinshaw
Malcolm D
MD
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D003460:Crystallization; D011756:Diphosphates / Q000494:pharmacology; D006801:Humans; D008969:Molecular Sequence Data; D025221:Phosphofructokinases / Q000737:chemistry* / Q000235:genetics; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D014346:Trypanosoma brucei brucei / Q000201:enzymology*; D014961:X-Ray Diffraction
D011756:Diphosphates; D000255:Adenosine Triphosphate; D025221:Phosphofructokinases