O-mycoloylated proteins from Corynebacterium: an unprecedented post-translational modification in bacteria.
O-acylation of proteins was known only in a few eukaryotic proteins but never in bacteria. We demonstrate, using a combination of protein chemistry and mass spectrometry, the occurrence of three O-acylated polypeptides in Corynebacterium glutamicum, PorA, PorH, and an unknown small protein. The three polypeptides are O-substituted by mycolic acids, long chain alpha-alkyl and beta-hydroxy fatty acids specifically produced by members of the Corynebacterineae suborder. To date these acids were described only as esterifying trehalose and arabinogalactan, and less frequently glycerol, important components of the highly impermeable outer barrier of Corynebacterineae. We show that the post-translational mycoloylation of PorA occurs at Ser-15 and is necessary for the pore-forming activity of C. glutamicum.
Huc
Emilie
E
Centre National de la Recherche Scientifique, Département Mécanismes Moléculaires des Infections Mycobactériennes, Institut de Pharmacologie et de Biologie Structurale, 205 route de Narbonne, F-31077 Toulouse Cedex 04, France.
Meniche
Xavier
X
Benz
Roland
R
Bayan
Nicolas
N
Ghazi
Alexandre
A
Tropis
Marielle
M
Daffé
Mamadou
M
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D003352:Corynebacterium / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions; D015640:Ion Channel Gating; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009171:Mycolic Acids / Q000737:chemistry / Q000378:metabolism*; D018272:Porins / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational
D001426:Bacterial Proteins; D009171:Mycolic Acids; C422458:PorA protein, Corynebacterium glutamicum; D018272:Porins