TABLE 1

Chimeric Nu1 alleles used in this study

Allele (motif segment origin)aRemarksReference
Nu1hy51 (H21 T21 H21 w21)Codons 1–103 derived from small terminase subunit gene 1 of phage 21.Frackman et al.(1985)
Nu1hy1 (Hλ Tλ H21 w λ)Produces gpNu1 with the four amino acids of the recognition helix replaced with those of 21's gp1.de Beer et al. (2002)
Nu1hy2 (H21 T21 H21 w λ)Codons 1–24 derived from phage 21's 1 gene. Small subunit residues derived from phage 21's gp1 include the amino terminus and the helix-turn-helix motif.de Beer et al. (2002)
Nu1hy3 (H21 Tλ H21 w λ)Small subunit differs from gpNu1 by two amino acids of the support helix and four amino acids of the recognition helix being replaced with those of 21's gp1.This work
Nu1hy4 (Hλ T21 H21 w λ)Small subunit differs from gpNu1 in four amino acids of the recognition helix and three amino acids of the turn being replaced with those of 21's gp1.This work
  • a Origins of gpNu1 segments of the winged helix-turn-helix DNA-binding motif, as described in materials and methods.