N-terminal acetylation of ectopic recombinant proteins in Escherichia coli.
N-terminal acetylation is a protein modification common in eukaryotes, but rare in prokaryotes. Here, we characterized five mammalian stathmin-like subdomains expressed in Escherichia coli by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nanoESI Q-TOF tandem mass spectrometry. We revealed that RB3(SLD) and RB3'(SLD) are N(alpha)-acetylated, whereas SCG10(SLD) and SCLIP(SLD), although identical up to residue 6, are not, as well as stathmin. To assess the influence of the N-terminal sequences on N(alpha)-acetylation, we exchanged residues 7 and 8 between acetylated RB3(SLD) and unacetylated SCG10(SLD), and showed that it reversed the acetylation pattern. Our results demonstrate that ectopic recombinant proteins can be extensively N(alpha)-acetylated in E. coli, and that the rules governing N(alpha)-acetylation are complex and involve the N-terminal region, as in eukaryotes.
Charbaut
Elodie
E
U440 INSERM/UPMC, Institut du Fer à Moulin, 17 rue du Fer à Moulin, 75005 Paris, France.
Redeker
Virginie
V
Rossier
Jean
J
Sobel
André
A
D000107:Acetylation; D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000378:metabolism*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D011994:Recombinant Proteins