Purification and characterization of a DNA-binding recombinant PREP1:PBX1 complex

Area of Science:

• Molecular Biology
• Structural Biology
• Protein Biochemistry

Background:

• Human PREP1 and PBX1 are homeodomain transcriptional factors with incompletely characterized biochemical and structural properties.
• Expression of full-length recombinant PREP1 and PBX1 in E. coli is hindered by low yield, instability, and insufficient purity, impeding structural studies.

Purpose of the Study:

• To develop a method for producing large quantities of soluble, pure, and active recombinant human PREP1:PBX1 complex.
• To facilitate detailed structural and biochemical characterization of the PBX1:PREP1 complex.

Main Methods:

• Cloning of PREP1 and PBX1 cDNAs into a dicistronic vector with an N-terminal glutathione S-transferase (GST) tag.
• Co-expression and co-purification of the PBX1:PREP1 complex.
• Production of C-terminally truncated complexes for enhanced stability and structural studies.

Main Results:

• Successful co-expression and co-purification of a stable PBX1:PREP1 complex.
• Development of C-terminally truncated complexes that maintain DNA-binding activity and exhibit improved stability.
• Achieved production of large amounts of soluble, pure, and active recombinant human PBX1:PREP1 complex.

Conclusions:

• The developed co-expression and purification strategy enables the production of stable, active recombinant human PBX1:PREP1 complex.
• This provides a foundation for further structural and biochemical investigations of these important transcriptional factors.
• The truncated versions offer a more tractable system for structural biology applications.