Figure 7.

Specificity of MlghC and DdahC for heptose versus mannose. DdahA and MlghB were incubated with GDP-manno-heptose or GDP-mannose; both enzymes were removed by ultrafiltration, and the products were incubated with MlghC or DdahC in the presence of NADPH. All reactions comprise residual DdahA and MlghB reaction products as defined in Figures 1 and 2. A and B, CE traces of reactions performed on GDP-6-deoxy-4-keto-mannulose (A) or heptulose (B). PI, PII, and PIII denote new products arising from mannose-based P4’ and P1’. P5γ and P5α are heptose-based reduction products of MlghC and DdahC, respectively, as described in Figure 1. C–F, time course of substrate conversion for reactions performed in parallel with heptose (D and F) versus mannose (C and E) for MlghC (C and D) or DdahC (E and F). The procedure and stoechiometries used to achieve equimolar substrate amounts for all reactions are detailed in Experimental procedures section. This is a representative example of 2 independent experiments. CE, capillary electrophoresis.