A-phosphoglucomutase

Cyclophilin Carbonic anhydrase Iriose phosphate isomerase Carboxypeptidase A Phosphoglucomutase Succinyl-CoA transferase Urease... 

PGMs are named for the anomer of GIP on which they act a-phosphoglucomutase (a-PGM) acts on the a-C(l) anomer of GIP, while /3-PGM catalyzes the reaction of the /3-C(l) anomer. Both mutases employ Mg as a cofactor. 

Figure 6.1 Sequential cascade reaction for the synthesis of dTDP-2,6-dideoxyhexoses. (a) Phosphoglucomutase, dTDP-GIc pyrophosphoryiase (RmiA), pyrophosphatase, (b) dTDP-Gic 4,6-dehydratase (RmlB), (c) 3,5-epimerase (RmiC), 4-keto reductase (RmiD), and (d) NaBH [81].

Leloir110(a) has described a conversion of D-mannosyl phosphate to D-mannose 6-phosphate by phosphoglucomutase, and here, too, the reaction requires catalytic quantities of a-D-glucose 1,6-diphosphate. The role of the latter is probably to generate a-D-mannose 1,6-diphosphate as follows. 

Phosphoglucomutase acts not only on D-glucose and D-mannose phosphates (see p. 204) but also on D-ribose phosphates, the interconversion of D-ribosyl phosphate and D-ribose 5-phosphate being similarly accelerated by D-glucose 1,6-diphosphate,193 which appears to generate D-ribose 1,5-diphos-phate as cofactor.199(a) (b) (o) D-Ribose 5-phosphate is formed from D-ribose and ATP in the presence of yeast ribokinase.m... 

TAUBERGER, E., FERNIE, A.R., EMMERMANN, M., KOSSMANN, J., WILLMITZER, L., TRETHEWEY, R.N., Antisense inhibition of plastidial phosphoglucomutase provides compelling evidence that potato tuber amyloplasts import carbon from the cytosol in the form of glucose-6-phosphate, Plant J., 2000, 23, 43-53. 

G5. Ginsburg, V., and Neufeld, E. F., Inhibition of phosphoglucomutase by galactose-1-phosphate. A possible factor in galactose toxicity. Am. Chem. Soc., 132nd Meeting, New York, N.Y., 1957, p. 27C. 

Phosphoglucomutase was isolated by the Coris and crystallized by Najjar. Its mechanism of action was suggested from experiments by Leloir in 1951 using [32P]. The enzyme is a phosphoprotein. Leloir showed that the phosphate group was transferred from the enzyme to G-1-P in the course of the reaction to give G-1,6 diP, which then donated the phosphate from its 1-position back to the enzyme, releasing G-6-P ... 

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