Fig. 7.

The VcNFeoB NTPase domain binds GDP and GMP-PNP similarly to GTP-specific NFeoB domains. Representative ITC thermograms (top) and ΔH vs. molar ratio traces (bottom) of WT (left) and N150T (right) VcNFeoB titrated with either GDP (a, b) or GMP-PNP (c, d). All datasets have been corrected for nucleotide dilution into buffer in the absence of protein. The strength of binding for GDP to both WT (3.18 μM ± 0.23 μM) and N150T VcNFeoB (3.60 μM ± 0.36 μM) are nearly identical, with both having a single binding site (N ≈ 1). The strength of binding for GMP-PNP to WT VcNFeoB (121.23 μM ± 34.13 μM) is slightly weaker than binding to N150T VcNFeoB (93.95 μM ± 15.63 μM), but both reveal a single binding site (N ≈ 1). All values were determined in triplicate and represent the mean ± one standard deviation of the mean.