Q-mediated late gene transcription of bacteriophage lambda: RNA start point and RNase III processing sites in vivo.

The location of the RNA start point of in vivo Q-activated late gene RNA of bacteriophage lambda has been determined to be identical to the start point of in vitro 6 S RNA. The 6 S RNA is made early in infection and is efficiently antiterminated by Q. Two RNase III cut sites are located within Q-dependent RNA sequences, 209 and 270 bp from the beginning of the late transcript, and lie on the stem of an inverted repeat which has features in common with previously described RNase III processing sites.

Regulation of transcription and DNA replication of bacteriophage phi 80.

Transcriptional mapping and DNA replication measurements have been used to characterize a series of phi 80 suppressor-sensitive mutants which are defective in genes 15, 14, 16, and 17. These genes are localized within the inner right arm of the vegetative phi 80 DNA genome. The sus326 mutation in gene 15 leads to a decrease in major leftward (pL-att80) RNA levels and to a marked pleiotropic reduction in major rightward RNA synthesis; however, phi 80 DNA synthesis is reduced only moderately (about two-fold).

Effect of cI repressor level on thymineless and spontaneous induction; specificity of lambda RNA transcription.

To determine the role of the cI repressor in induction provoked by thymine deprivation, we have analyzed lambda messenger RNA made during and the effect of cI repressor levels on thymineless induction. During thymineless induction, the l- and r-strand transcription of lambda is restricted to the "early" and "delayed early" RNA. This transcriptional pattern is similar to that reported for lambda mutants defective in DNA synthesis.