RF4
(Bacterial strain #62072)

• Purpose: BL21(DE3)-based E. coli amino acid auxotrophic host strain used for selective isotope labeling. aspC tyrB genes deleted.
• Depositing Labs: Robert Gennis, Toshio Iwasaki
• Publication: Lin et al Methods Enzymol. 2015;565:45-66. doi: 10.1016/bs.mie.2015.05.012. Epub 2015 Jun 10.

Backbone

• Vector backbone: none

Growth in Bacteria

• Bacterial Resistance(s): None
• Growth Temperature: 37°C
• Growth Strain(s): RF4 (aspC tyrB)
• Copy number: Unknown

Gene/Insert

• Gene/Insert name: none

Resource Information

• Supplemental Documents:
  • PCR primers
  • PCR data RF4

Terms and Licenses

• Academic/Nonprofit Terms:
  • UBMTA
• Industry Terms:
  • Not Available to Industry

Depositor Comments

Genotype = aspC tyrB
Precursor strain = RF3
modified from the parent Escherichia coli BL21 CodonPlus (DE3)-RIL
Selective amino acid labeling (and/or requirement) = Asp++++, Tyr, (Phe)

++++RF4, RF5, and RF13 strains have knockouts in both aspC and tyrB genes and therefore require the presence of L-Asp (but not L-Glu) for growth in M63 minimal medium. These strains can be used for selective labeling of selected aromatic amino acid(s) such as Tyr (RF4, RF5, RF13) and/or Trp (RF13). We have NOT tested if these strains could also be used for selective Asp labeling studies (under investigation).

Each target gene was deleted from the chromosome of BL21 (DE3) E. coli strain using λ-Red recombination system.

Supplemental documents contain a list of PCR primers used for verification of each knocked-out gene as well as an image showing PCR results for this strain.

This work is supported in part by JSPS-NSF International Collaborations in Chemistry (ICC) research grant.