FINE CONTROL OF PHOSPHOPYRUVATE CARBOXYLASE ACTIVITY IN ESCHERICHIA COLI,
Abstract
Previous studies with mutants of Salmonella typhimurium and Escherichia coli, which fail to grow on glucose-salts media unless such media are supplemented with intermediates of the tricarboxylic acid cycle or direct precursors thereof, have shown that the carboxylation of phosphoenolpyruvate (CH2=C.(COOH).O.PO3H2 + CO2 yields HOOC.CH2.CO.COOH + Pi) is necessarily involved in the maintenance of the tricarboxylic acid cycle: this reaction serves to replenish the cycle with C4-compounds, as intermediates of that cycle are revoved in the course of biosynthesis. It was difficult to explain why CoASAc and citrate synthase should be so much more efficient a trapping agent for labelled oxaloacetate than was malate dehydrogenase and NADH2, even when the extracts were supplemented with crystalline malate dehydrogenase: this observation suggested that CoASAc played a role in this system additional to its function as a trapping agent. This suggestion was confirmed with a mutant AB1623 of E. coli K-12.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 07, 1964
- Accession Number
- AD0617990
Entities
People
- H. L. Kornberg
- J. L. Canovas
Organizations
- University of Leicester