Identification of recombinant HupS protein in vitro acetylation extent

Nucleoid-associated proteins (NAPs) are critical during the process of chromatin compaction in Streptomyces soil bacteria. HupS is one of the two NAPs encoded in the Streptomyces genome. Its unique C-terminal domain, rich in lysine repeats (LR domain), is alike to the H2B histone found in eukaryotic cells or the HupB protein found in Mycobacterium. Project study aim was to investigate if the lysine residues of the HupS LR domain undergo the posttranslational reversible lysine acetylation process. Mass spectrometry approach was employed in order to identify the number of acetyl groups attached to the recombinantly produced and subsequently purified HupS protein after it was subdue to an in vitro acetylation reaction with acetyl phosphate (AcP).