Cytotoxic hammerhead ribozymes.
Small catalytic RNA molecules of the hammerhead ribozyme type were found to have cytotoxic effects unrelated to their intended activity. An expression library of ribozyme sequence variants was constructed in a recA-deficient strain of Escherichia coli such that individual library members differed in regions designed to form base pairs with human immunodeficiency virus-1 (HIV-1) tat mRNA. The parental ribozyme and many variants exhibited a bacteriostatic effect. One variant studied in detail was also bactericidal. When its expression was induced, ribozyme-dependent inhibition of bacterial growth was not observed in recA+ or recA+ lexA3 (Ind-) cells, suggesting that the recombination function of the RecA protein, not the absence of the SOS response, is sufficient to alleviate the cytotoxic effect. These data document the need for careful testing for toxic effects during intracellular studies of ribozyme action.
Levitz
R
R
Public Health Research Institute, New York, NY 10016, USA.
Dong
Y
Y
Wang
J Y
JY
Jeng
S W
SW
Chen
C R
CR
Wang
J W
JW
Zhao
X
X
Zhou
J
J
Lu
T
T
Drlica
K
K
D001483:Base Sequence; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D015696:Gene Products, tat / Q000378:metabolism; D015497:HIV-1; D008969:Molecular Sequence Data; D012313:RNA / Q000494:pharmacology; D016337:RNA, Catalytic / Q000096:biosynthesis / Q000235:genetics / Q000633:toxicity*; D012367:RNA, Viral / Q000378:metabolism; D011938:Rec A Recombinases / Q000235:genetics*; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D016337:RNA, Catalytic; D012367:RNA, Viral; C039919:RNA, recombinant; D054322:tat Gene Products, Human Immunodeficiency Virus; D012313:RNA; D011938:Rec A Recombinases