CGSC Strain#: 701
Strain Designation: W3659      Source of Strain: A. Richter
Sex: F- Chromosomal Markers: fhuA24, lacY40, galK2(Oc), λ^-, TP3, malB5::Sfa(att)
Strain Comments:

• his.
• sfa-3 is a sex-factor-attachment-site in malB. When infected with F, this strain gives rise to an Hfr with the point of origin of Richter's Hfr3 (in malB). Note the transposition of
• It is inserted between proAB and lac.
• lacY40-- When lacY40 and lac ? appear in a genotype, it is meant to indicate that lacY40 has become more stable due to a second mutation, perhaps in lac occurring in W3828.
• galK2(Oc)-- is a GAA(glu) to TAA(ochre) mutation, residue 134. Oller et al.1993. Apparently non-suppressible, since all revertants found were at the ochre site.
• TP3-- is F42-114 inserted between his (44) and thyA (68.8) his lacI-A > thyA
• malB5::Sfa(att)-- sfa-3 is a sex factor-attachment-site in malB. When infected with F, this strain gives rise to an Hfr with the point of origin of Richter's Hfr3 (in malB).
• galK2(Oc) was formerly called gal₂
• Oc = ochre(UAA) mutation

References:

• Richter, A. 1961. Attachment of wild type F factor to a specific chromosomal region in a variant strain of Escherichia coli K12: the phenomenon of episomic alternation. Genet.Res. 2:333-345
• Dewitt, SK, EA Adelberg 1962. The Occurrence of a Genetic Transposition in a Strain of Escherichia Coli. Genetics 47(5):577-85.