Dictyostelium discoideum characteristics

Fig. 1. Ribbon diagrams of Dictyostelium discoideum G-actin (Matsuura et al., 2000) and the Ascaris suum aMSP dimer (Bullock et al., 1996) at the same magnification. Actin consists of four subdomains that surround a nucleotide-binding cleft. The G-actin molecule is asymmetric, so that when it polymerizes, the filament it forms has a characteristic polarity and its two ends differ structurally. By contrast, MSP does not contain a nucleotide binding site and the polymerizing unit is a dimer in which the two MSP molecules are related by twofold rotational symmetry. Polymerization produces filaments composed of two helical subfilaments in which the dimers twofold axes are oriented perpendicular to the helix axis. Consequently, the MSP helices have no polarity and the subfilament ends are identical structurally (Bullock et al., 1998). Reproduced from The Journal of Cell Biology, 2000, vol. 149, pp. 7-12 by copyright permission of the Rockefeller University Press.

Henderson, E.J. 1975. The cyclic adenosine 3 5 -monophosphate receptor of Dictyostelium discoideum. Binding characteristics of aggregation-competent cells and variation of binding levels during the life cycle. J. Biol. Chem. 250 4730-6. 

Newell and coworkers found that, during particular stages of fruit construction in Dictyostelium discoideum, four functionally related enzymes accumulated, reached characteristic levels of specific activity, and then disappeared partly or completely. These enzymes were UDP-d-glucose pyrophosphorylase, trehalose 6-phosphate synthetase, UDP-d-galactose 4-epimerase, and UDP-D-galactose polysaccharide n-galactosyl transferase. 

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