Dominance in lambda S mutations and evidence for translational control. Academic Article uri icon


  • Phenotypic analysis of a collection of point mutations in the lysis gene S of bacteriophage lambda indicates that many of the S alleles exhibit at least partially dominant character, suggesting that the S gene product (gpS) must oligomerize to achieve its lethal membrane effect. Moreover, mutations found 5' to the coding sequence also show a dominant character and appear to define a site, designated sdi (structure directed initiation) where mRNA secondary structure controls the choice of initiation codons. We propose that formation of the sdi structure occludes the consensus Shine-Dalgarno sequence and results in initiation at the Met3 codon, generating a lethal 105 residue polypeptide. The model predicts that, in the absence of the sdi stem-and-loop, initiation occurs at the Met1 codon, generating a 107 residue polypeptide, which is a non-lethal inhibitor of lysis. In support of the model, alteration of the first codon was achieved using site-directed mutagenesis, resulting in an S allele that is more lethal and induces lysis significantly sooner than the wild-type.

published proceedings

  • J Mol Biol

altmetric score

  • 3

author list (cited authors)

  • Raab, R., Neal, G., Sohaskey, C., Smith, J., & Young, R.

citation count

  • 79

complete list of authors

  • Raab, R||Neal, G||Sohaskey, C||Smith, J||Young, R

publication date

  • January 1988