GROWTH OF ESCHERICHIA-COLI IN ACETATE AS A SOLE CARBON SOURCE IS INHIBITED BY ANKYRIN-LIKE REPEATS PRESENT IN THE 2',5'-LINKED OLIGOADENYLATE-DEPENDENT HUMAN RNASE-L-ENZYME

Expression of low levels of the 2',5'-linked oligoadenylate-dependent human RNase L, an enzyme induced by interferons, is highly toxic in Es cherichia coli. This protein contains an ankyrin domain responsible fo r RNase L toxicity. The only known ORF in E. coli containing ankyrin r epeats is yjaC in the acetate metabolic cluster. We have investigated if expression of mutant forms of RNase L interfere with metabolism of acetate in E. coli. Our findings demonstrate that E. coli expressing R Nase L ankyrin repeats is unable to grow in medium containing acetate as the sole carbon source, while it can grow when expressing other dom ains of the protein. This defect correlates with a severe decrease in the levels of induction of enzymes in the glyoxylate bypass.