Transdominant inhibition of Moloney murine leukemia virus proliferation by defective mutants of reverse transcriptase

To investigate the dominant-negative inhibition of Moloney murine leukemia virus (Mo-MuLV) proliferation by polymerization-defective mutants of reverse transcriptase (RT), Ne constructed several plasmids harboring the Mo-MuLV RT gene in which the YVDD sequence, one of the conserved sequences in RNA-dependent polymerases, mas altered, aad then transformed mouse NIH3T3 cells and Escherichia coli with the mutant plasmids. Mouse NIH3T3 cells expressing these mutant RT genes were highly resistant to Mo-MuLV proliferation, The mutant RT expressed in E. coli exhibited no polymerization activity, but; it retained its binding activity to the template RNA and inhibited in vitro poly(dG) synthesis occurring with the wild-type RT, These results suggest that the competition for binding of the two types of enzymes to the template is responsible fur the resistance to Mo-MuLV proliferation and that the YVDD sequence of Mo-MuLV may be a good target for dominant-negative inhibition of retroviral proliferation.