FIG 1.
Enzymology and bioenergetics of the putative acetogenic pathway in T. pallidum. The metabolites of the pathway are shown near the bottom of the figure. Enzymes are gray ovals. Membrane proteins are green rectangles. The yellow rectangles are flavoproteins. The speculative role for TP0038 in d-lactate import is denoted by a question mark next to the arrow indicating transport. The substrate-level phosphorylation in the acetogenic pathway is labeled SLP and is enclosed in a blue box. Reactions utilizing or generating the chemiosmotic gradient are in a pink box labeled C/O. TP0037 is identified as the d-LDH in this study, and the names of the gene products that putatively fulfill the enzymatic functions in the acetogenic pathway or d-lactose transport are shown in italics. Abbreviations: d-LDH, d-lactate dehydrogenase; PFOR, pyruvate:flavodoxin oxidoreductase; Pta, phosphate acetyltransferase; AckA, acetate kinase; Fld, flavodoxin; CM, cytoplasmic membrane; Pi, inorganic phosphate; acetyl-P, acetyl phosphate; Nu, nutrient.