Hecker M, Schroeter A
J Basic Microbiol. 1985;25(5):341-7. doi: 10.1002/jobm.3620250511.
Synthesis of alkaline phosphatase in Escherichia coli is derepressed under phosphate starvation in the stringent strain CP78 as well as in its relaxed counterpart CP79. During limitation of phosphate as well as of amino acids a decrease of enzyme activity is observed, especially in the relaxed strain, which can not produce ppGpp under this conditions. After phosphate limitation synthesis of ppGpp is not stimulated and the kinetics of RNA synthesis is similar in both strains. We suggest that ppGpp is not directly involved in the regulation of gene expression during phosphate starvation.
在严格型菌株CP78及其松弛型对应菌株CP79中，大肠杆菌碱性磷酸酶的合成在磷酸盐饥饿条件下会去阻遏。在磷酸盐以及氨基酸受限期间，会观察到酶活性下降，尤其是在松弛型菌株中，该菌株在此条件下无法产生ppGpp。在磷酸盐受限后，ppGpp的合成未受刺激，且两菌株中RNA合成的动力学相似。我们认为，ppGpp在磷酸盐饥饿期间不直接参与基因表达的调控。
