Figure 5.

Polder-style electron density maps of the THF-binding loop in soybean SHMT8. Positions of residues 130 and 358 are noted. Maps are contoured at 3 σ, and density is shown spanning residues 377–387. A, the well-ordered loop in the Essex SHMT8 ternary complex with PLP-Gly and FTHF. B and C, show density for the loop in the Essex SHMT8 complexes with PLP and PLP-Gly, respectively. D and E, corresponding complexes with Forrest SHMT8, for comparison with those of Essex. Note the more extensive partial density for the loop in the Forrest complexes, suggesting a change in loop mobility caused by the substitutions at residues 130 and 358.