Cloning, expression and characterization of Mycobacterium tuberculosis lipoprotein LprF.
Lipoproteins are well known virulence factors of bacterial pathogens in general and of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, in particular. Lipoprotein lipidation between Gram-positive and Gram-negative bacteria differs significantly as these are di- and triacylated, respectively. Little is known about the lipid anchor of mycobacterial lipoproteins. We reported recently that mycobacterial LppX, a lipoprotein involved in synthesis of cell wall components is triacylated, although mycobacteria are classified as GC-rich Gram-positive bacteria. We here exploited the model organism Mycobacterium smegmatis for the expression of Mtb LprF and characterized N-terminal modifications at the molecular level. LprF is a putative lipoprotein of Mtb involved in signaling of potassium-dependent osmotic stress. LprF is extensively modified in a mycobacterium-specific manner by a thioether-linked diacylglyceryl residue with one ester-bound tuberculostearic- and one C16:0 fatty acid and additionally by a third N-linked C16:0 fatty acid, and a hexose.
Brülle
Juliane K
JK
Institute of Medical Microbiology, University of Zurich, Gloriastr 30/32, CH-8006 Zurich, Switzerland.
Grau
Thomas
T
Tschumi
Andreas
A
Auchli
Yolanda
Y
Burri
Reto
R
Polsfuss
Silke
S
Keller
Peter M
PM
Hunziker
Peter
P
Sander
Peter
P
D000595:Amino Acid Sequence; D008074:Lipoproteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D020102:Mycobacterium smegmatis / Q000378:metabolism; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D008074:Lipoproteins; D011994:Recombinant Proteins