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

Figure 10

LpxK. (a) LpxK bound to AMP-PCP ATP analogue (PDB: 4ITL) [70]. Spectrum coloring begins with blue at the N-terminus. (b) Residues involved in AMP-PCP binding from (a). Distances for hydrogen-bond and salt-bridge interactions are shown with distances in Ångstroms as follows: 3.0 from adenine N6 to Q240 Oε and 3.5 to R206 Nη1, 3.0 from adenine N7 to Q240 Nε, 2.8 from ribose 3′-hydroxyl to T52 Oγ, 2.9 from β-phosphate to S49 N and 3.1 to K51 N and 2.7 to T52 N and 2.6 to T52 Oγ, 3.0 from α-phosphate to G50 N and 2.6 to Y187 Oη, 3.4 from ribose 2′-hydroxyl to K280 N 2.8 from D99 Oδ1 to H261 Nδ, 3.0 from K51 Nζ to D139 Oδ1 and 2.7 to γ-phosphate, 2.9 and 2.8 from γ-phosphate to E100 Oε2/1, 3.2 from K280 Nζ to water, and 2.2, 3.0, and 3.0 from this water to the phosphates. (c) Hydrophobicity surface of LpxK bound to lipid IV_A (PDB: 4LKV) [72]. Hydrophobicity is shown in an orange-blue scale with blue representing the hydrophilic end. (d) Residues involved in binding lipid IV_A from (c). Distances in Ångstroms for hydrogen-bonds and salt-bridges are as follows: 2.4 from 6′-hydroxyl to R72 Nη2 and 3.2 from the distal glucosamine ring O 3.4 from 1-phosphate to R119 Nη1 and 3.2 to H143 Nδ and 2.9 from R72 Nη1, and 3.3 from 4-hydroxyl to E117 Oε.

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