pET21-Streptavidin-K121R
(Plasmid #89880)

• Purpose: Streptavidin that has unimpaired biotin binding after dye labeling
• Depositing Lab: Mark Howarth
• Publication: Jacobsen et al Cell Chem Biol. 2017 Jul 17. pii: S2451-9456(17)30229-5. doi: 10.1016/j.chembiol.2017.06.015.

Backbone

• Vector backbone: pET21
• Backbone manufacturer: Novagen
• Backbone size w/o insert (bp): 5400
• Total vector size (bp): 5802
• Vector type: Bacterial Expression

Growth in Bacteria

• Bacterial Resistance(s): Ampicillin, 100 μg/mL
• Growth Temperature: 37°C
• Growth Strain(s): DH5alpha
• Growth instructions: DH5alpha for propagation of the plasmid. Bl21[DE3] or similar required for protein expression.
• Copy number: Low Copy

Gene/Insert

• Gene/Insert name: Streptavidin-K121R-Glutamate_Tag
• Alt name: SAe-K121R
• Species: E. coli
• Insert Size (bp): 402
• Mutation: K121R
• Tag / Fusion Protein:
  • 6 glutamate tag (C terminal on insert)

Cloning Information

• Cloning method: Unknown
• 5′ sequencing primer: T7F
• 3′ sequencing primer: T7R

Terms and Licenses

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

Depositor Comments

The residue numbering is based 1986 paper from Charles Cantor: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC339579 (see Figure 3)
In the original sequence, there is a signal peptide and N-terminal sequence that are proteolytically processed. Thus, the most common version is Core Streptavidin, which starts at residue 13 and ends at residue 139, as shown here: http://www.jbc.org/content/270/47/28204.long (see Figure 1)