CGSC Strain#: 5261
Strain Designation: Hfr 3000 X74      Source of Strain: F. Jacob
Sex: Hfr    Point of Origin#: 1   Map Position: 96.80   Direction of Marker Transfer: Clockwise
Chromosomal Markers: Δ(codB-lacI)3, λ^-, e14-, relA1, spoT1, thiE1
Strain Comments:

• Δ(codB-lacI)3-- is a deletion of the entire lac operon, from the strain Hfr 3000 X74 of Jacob. Refs. on extent of deletion: Sung et al.1987,J.Bact.169:2639; Gerdes et al.2001
• Δ(codB-lacI)3-- Shown by Durfee et al. to extend from codon 292 of yahG through mhpE
• Δ(codB-lacI)3-- Shown by Ferrandez et al. 1997 to extend to mhpD
• e14--- : Loss of the e14 element makes the strain McrA^-.
• spoT1-- In addition to the 6bp insertion, there is a C to T transition resulting in an H257Y substitution.
• Δ(codB-lacI)3 was formerly called Δ(yahG-mhpE)
• Δ(codB-lacI)3 was formerly called X74
• Δ(codB-lacI)3 was formerly called DE(lac)6
• Δ(codB-lacI)3 was formerly called Δlac74
• Δ(codB-lacI)3 was formerly called Δ(lac)3
• thiE1 was formerly called thi-1

References:

• Beckwith, J.R., E.R. Signer 1966. Transposition of the lac region of Escherichia coli. I. Inversion of the lac operon and transduction of lac by phi 80. J.Mol.Biol. 19:254-265