Truncated forms of the recombinant Escherichia coli ADP-glucose pyrophosphorylase: the importance of the N-terminal region for allosteric activation and inhibition.
Truncated forms of Escherichia coli ADPglucose pyrophosphorylase were constructed using recombinant DNA techniques. A truncated form of the enzyme having the first 11 amino acid residues from the N-terminus and 2 amino acid residues from the C-terminus deleted was found to be highly active in absence of activator. A 1.6-fold activation by 1.5 mM fructose 1,6 bis-phosphate was observed for the truncated enzyme as compared to the 30-fold activation seen for the intact enzyme. Inhibition of the truncated enzyme by AMP was less than that seen with the intact enzyme. Similar properties were displayed by an enzyme truncated only at the N-terminal. Conversely, the C-terminal truncated enzyme shortened by 2 amino acid residues at the C-terminus is as sensitive as the intact enzyme to activation and inhibition. These results suggest that the N-terminal region is required for allosteric regulation of the enzyme.
Wu
M X
MX
Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA.
Preiss
J
J
D000249:Adenosine Monophosphate / Q000494:pharmacology; D000494:Allosteric Regulation; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D051599:Glucose-1-Phosphate Adenylyltransferase; D007700:Kinetics; D008024:Ligands; D008274:Magnesium / Q000378:metabolism; D009713:Nucleotidyltransferases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D013379:Substrate Specificity
D017931:DNA Primers; D004791:Enzyme Inhibitors; D008024:Ligands; D010446:Peptide Fragments; D011994:Recombinant Proteins; D000249:Adenosine Monophosphate; D009713:Nucleotidyltransferases; D051599:Glucose-1-Phosphate Adenylyltransferase; D008274:Magnesium