Single-site phosphorylation within the His-tag sequence attached to a recombinant protein

Himanshu Singh (1) , Deepshikha Verma (1) , Benjamin Bardiaux (2)

1 TIFR - Tata Institute for Fundamental Research
2 Bioinformatique structurale - Structural Bioinformatics

We report the observation of single-site phosphorylation in a His-tag sequence N-terminally attached to a recombinant protein (UVI31+) in vitro. This modification was detected at position 23 at a serine residue of the His-tag sequence encoded by the vector pET28a. Furthermore, the phosphorylated tag sequence was found to be dephosphorylated by the action of alkaline phosphatases. The functional activity and dynamics of the protein carrying the His-tag sequence were unchanged after phosphorylation. The possibility of phosphorylation within the N-terminal His-tag demonstrates that care has to be taken upon analysis of post-translational modifications via mass spectrometry for recombinant protein expression strategies.

Keywords: His-tag; MALDI-TOF; NMR; Phosphorylation; Recombinant protein; pET28a

Domains: Chemical Sciences; Life Sciences [q-bio]; Biochemistry, Molecular Biology

Himanshu Singh, Deepshikha Verma, Benjamin Bardiaux. Single-site phosphorylation within the His-tag sequence attached to a recombinant protein. Analytical Biochemistry, 2019, 570, pp.62-64. ⟨10.1016/j.ab.2019.02.001⟩. ⟨pasteur-02329972⟩