Fig. 3: Activation of the VTC complex by SPXVtc4-sensed InsP6 messenger. | Nature Communications

Fig. 3: Activation of the VTC complex by SPXVtc4-sensed InsP6 messenger.

From: The cytoplasmic synthesis and coupled membrane translocation of eukaryotic polyphosphate by signal-activated VTC complex

Fig. 3

a Electrostatic surface (Top) and molecular surface (Bottom) representation of SPX and TTM domains in InsP6-activated Vtc1/Vtc3/Vtc4R264A/R266A/E426N complex, displayed in the same perspective. Electrostatic potential is calculated with the APBS plugin in PyMOL, colored and displayed in a scale from red (−5 kT/e) to blue (+5 kT/e). SPXVtc4 PBC (Y22, K26, K133) and KSC (K129, K132, K136) residues are shown in stick representation. b, c Assay of VTC-catalyzed polyP synthesis. 5 μM protein complex were used and reactions were performed at required InsP6 concentrations for 4 h. A commercial polyP with an average chain length of 60 residues was used as the marker. Wt, Vtc1/Vtc3/Vtc4; Vtc3SPX,PBC, Vtc1/Vtc3Y22F/K26A/K130A/Vtc4; Vtc4SPX,PBC, Vtc1/Vtc3/Vtc4Y22F/K26A/K133A; Vtc3SPX,KSC, Vtc1/Vtc3K126A/K129A/K133AVtc4; Vtc4SPX,KSC Vtc1/Vtc3/Vtc4K129A/K132A/K136A. Source data are provided as a Source Data file. The experiments were repeated three times independently with similar results.

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