CGSC Strain#: 4327
Strain Designation: K28      Source of Strain: M.C. Cappello
Sex: Hfr    Point of Origin#: 2A   Map Position: 12.20   Direction of Marker Transfer: Counterclockwise
Chromosomal Markers: garB10, fhuA22, phoA4(Am), serS14(ts), serC13, ompF627(T2R), serU132(AS), fadL701(T2R), relA1, pitA10, spoT1, rrnB-2, mcrB1, creC510
Strain Comments:

• In order to use the temperature sensitive marker in this strain, K.B. Low recommends the use of a medium containing a low salt concentration ( e.g. Luria Agar modified to contain only 0.05% NaC1)
• incubation at 44 degrees C, and examination of plates after 9 hours' incubation.
• phoA4(Am)-- is Garen's phoAS26 . It is suppressed by leuX151, glnV33(=supE33) and serU132(=supD32).
• spoT1-- In addition to the 6bp insertion, there is a C to T transition resulting in an H257Y substitution.
• rrnB-2-- : loss of spacer loop sequence
• creC510-- The constitutive phenotype is due to an R77P amino acid substitution
• creC510 was formerly called phoM510
• serU132(AS) was formerly called supD32
• serU132(AS) was formerly called Su1⁺
• Am = amber(UAG) mutation
• AS = amber(UAG) suppressor
• Const = constitutive
• T2R = T2 Resistant
• ts = Temperature Sensitive

References:

• Clarke, S.J., K.B. Low, W. Konigsberg 1973. Isolation and characterization of a regulatory mutant of an aminoacyltransfer ribonucleic acid synthetase in Escherichia coli K-12. J.Bacteriol. 113:1096-1103