FIG. 1.

Map of relevant region of the λ genome showing location of promoters (P), terminators (t), nut sites, and representative genes. Also shown are the regions of the nin deletion and the gene replacements. The λ recombination system (28) was used to replace λ sequences from nucleotides 31,351 to 34,700 in the standard λ sequence (6) with either the nusG or cat gene. (A) λ wild-type; (B) λnusG and λcam; (C) λnin. Below each genetic map are the patterns of transcription in both the presence and absence of N or Nus factors (A and B) or only in the absence of N or Nus factors (C).