5azi

Crystal structure of glycerol kinase from Trypanosoma brucei gambiense complexed with 4NP

spinqualitylabelsall models 5azi, resolution 2.45Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5azi is a 4 chain structure with sequence from Trypanosoma brucei gambiense. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.45Å Ligands: 4NP, GOL, TPO Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function D3KVM3_TRYBG Publication Abstract from PubMed BACKGROUND: In general, glycerol kinases (GKs) are transferases that catalyze phospho group transfer from ATP to glycerol, and the mechanism was suggested to be random bi-bi. The reverse reaction i.e. phospho transfer from glycerol 3-phosphate (G3P) to ADP is only physiologically feasible by the African trypanosome GK. In contrast to other GKs the mechanism of Trypanosoma brucei gambiense glycerol kinase (TbgGK) was shown to be in an ordered fashion, and proceeding via autophosphorylation. From the unique reaction mechanism of TbgGK, we envisaged its potential to possess phosphatase activity in addition to being a kinase. METHODS: Our hypothesis was tested by spectrophotometric and LC-MS/MS analyses using paranitrophenyl phosphate (pNPP) and TbgGK's natural substrate, G3P respectively. Furthermore, protein X-ray crystallography and site-directed mutagenesis were performed to examine pNPP binding, catalytic residues, and the possible reaction mechanism. RESULTS: In addition to its widely known and expected phosphotransferase (class II) activity, TbgGK can efficiently facilitate the hydrolytic cleavage of phosphoric anhydride bonds (a class III property). This phosphatase activity followed the classical Michaelis-Menten pattern and was competitively inhibited by ADP and G3P, suggesting a common catalytic site for both activities (phosphatase and kinase). The structure of the TGK-pNPP complex, and structure-guided mutagenesis implicated T276 to be important for the catalysis. Remarkably, we captured a crystallographic molecular snapshot of the phosphorylated T276 reaction intermediate. CONCLUSION: We conclude that TbgGK has both kinase and phosphatase activities. GENERAL SIGNIFICANCE: This is the first report on a bifunctional kinase/phosphatase enzyme among members of the sugar kinase family. Glycerol kinase of African trypanosomes possesses an intrinsic phosphatase activity.,Balogun EO, Inaoka DK, Shiba T, Tokuoka SM, Tokumasu F, Sakamoto K, Kido Y, Michels PAM, Watanabe YI, Harada S, Kita K Biochim Biophys Acta Gen Subj. 2017 Nov;1861(11 Pt A):2830-2842. doi:, 10.1016/j.bbagen.2017.07.028. Epub 2017 Aug 2. PMID:28778484 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glycerol kinase

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