Genetics of the Heme Pathway and Its Regulation

摘要: In the spring of 1984, author decided to study regulation heme biosynthetic enzymes and thereby contribute in a peripheral way B12 project. This review presents personal view pathway for biosynthesis its enteric bacteria Salmonella Typhimurium Escherichia coli. The chapter emphasizes genetic aspects with some historical perspective. It discusses what is known about these bacteria. HemA protein quite unstable cells growing normally, but it stabilized by more than 10-fold specifically under conditions limitation. suggests three simple models regulation. first model, ATP concentration vivo postulated decrease during heme-limited growth point that becomes limiting energy-dependent proteolysis. Second, when Lon ClpAP proteases act on HemA, Km might be higher other substrates. Finally, third model supposes protease-sensitive conformation formation disulfide bond, which favored cell has excess oxidation capacity.