The Regulation of Purine Utilization in Bacteria

摘要: Abstract The ability of rel+ cell strains Escherichia coli to take up nucleosides and bases convert them the corresponding ribonucleoside 5'-triphosphates is qualitatively dependent upon amino acids, much same as accumulate RNA. Restriction uptake in this case occurs under conditions that elicit guanosine 5'-diphosphate, 2'- or 3'-diphosphate (ppGpp) accumulation both phenomena are reversed by addition chloramphenicol. P-ribose-PP-dependent transport purine into membrane vesicles inhibited ppGpp, membrane-bound phosphoribosyltransferase activities. degree inhibition differs for different substrates; purines, approximates restrictions observed whole cells. Enzyme preparations obtained from rel- cells were equally ppGpp. Purified soluble 6-hydroxy phosphoribosyltransferase, which mediates membranous Inhibition not strictly competitive, but appears be less severe at high P-ribose-PP levels. Adenine was only mildly inhibitory effects ppGpp on due can account physiological