Current Progress in the Structural and Biochemical Characterization of Proteins Involved in the Assembly of Lipopolysaccharide

Figure 4

LpxC. (a) Ribbon structure of LpxC bound to its UDP-3-O-(R3-hydroxymyristoyl)-glucosamine product (PDB: 4MDT) [36]. Spectrum coloring begins with blue at the N-terminus. (b) Hydrophobicity surface of the structure in (a) with a orange-blue scale. Orange is more hydrophobic. (c) Residues involved in product binding from (a). Zinc coordination is shown in purple, and hydrogen-bond and salt-bridge interactions are shown in pink. Distances of interactions in Ångstroms are as follows: 1.9 from Zn²⁺ to H238 Nε, 2.0 from Zn²⁺ to H79 Nε, 2.0 from Zn²⁺ to D242 Oδ1, 1.9 from Zn²⁺ to phosphate O2, 2.5 from water to β-phosphate and 3.2 to α-phosphate and 3.0 to A266 N 3.2 from pyrophosphate bridging O and 2.8 from β-phosphate and 3.5 from glucosamine 6′-hydroxyl to K239 Nζ, 2.8 from β-hydroxyl to phosphate O1, 3.2 from water to F194 N and 2.9 to glucosamine 4′-hydroxyl, 3.1 from glucosamine 2′-amine to phosphate O3 and 2.7 to L62 O 2.6 from E78 Oε2 to phosphate O4, 2.4 from H265 Nε to phosphate O3, 3.5 from uracil O4 to D160 N 2.7 from D246 Oδ2 to H265 Nδ, and 3.5 from uracil N3 to D160 O.