CGSC Strain#: 4272
Strain Designation: Hfr 7-4      Source of Strain: W.K. Maas
Other Designations: MA1048
Sex: Hfr    Point of Origin#: 50   Map Position: 82.50   Direction of Marker Transfer: Clockwise
Chromosomal Markers: leuB6(Am), fhuA2::IS2, lacY1, glnX44(AS), gal-6, λ^-, hisG1, recA1, argG6, rpsL104, malT1(λ^R), xyl-7, mtlA2, metB1
Strain Comments:

• leuB6(Am)-- Suppressed by serU suppressor (supH)
• glnX44(AS)-- Mutation is a C to T transition at nucleotide 34 (3rd position of the anticodon)
• hisG1-- This mutation has been reported as either a frameshift or a 36 nt deletion
• recA1-- : Missense mutation, altered isoelectric point. Sequenced: G to A for Nuc. 720 (Gly 160 Asp).
• fhuA2::IS2 was formerly called fhuA2
• glnX44(AS) was formerly called su⁺_II
• glnX44(AS) was formerly called supE44
• glnX44(AS) was formerly called glnV44
• xyl-7 was formerly called xylA7
• = strep-resistant
• ::IS2 = Insertion of IS2
• Am = amber(UAG) mutation
• AS = amber(UAG) suppressor
• LamR = Lambda-resistant

References:

• Dubnau, E., W.K. Maas 1968. Inhibition of replication of an F' lac episome in Hfr cells of Escherichia coli. J.Bacteriol. 95:531-539