Lipid modification of prelipoproteins is dispensable for growth in vitro but essential for virulence in Streptococcus pneumoniae.
A Deltalgt (Lgt, lipoprotein diacylglyceryl transferase) isogenic mutant was obtained which indicates that lgt is not essential for cell growth in vitro, like in the Gram-positive bacterium Bacillus subtilis, but unlike in the proteobacteria Escherichia coli and Salmonella typhimurium. The mutation was transduced to a virulent strain. A 5 log attenuation was observed in a respiratory tract model of infection. Metabolic labeling by [U-14C]palmitate revealed the presence of eight to ten lipoproteins in the wild-type strain only, with molecular masses between 15 and 80 kDa. Our findings suggest a major difference in the role of lipoproteins in Gram-positive bacteria versus the proteobacteria.
Petit
C M
CM
GlaxoSmithKline Pharmaceuticals, Anti-Microbial and Host Defense, Collegeville, PA 19426-0989, USA. chantal_petit-1@sbphrd.com
Brown
J R
JR
Ingraham
K
K
Bryant
A P
AP
Holmes
D J
DJ
D000595:Amino Acid Sequence; D000818:Animals; D003114:Colony-Forming Units Assay; D004195:Disease Models, Animal; D004591:Electrophoresis, Polyacrylamide Gel; D050356:Lipid Metabolism; D008074:Lipoproteins / Q000378:metabolism; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D008969:Molecular Sequence Data; D012140:Respiratory Tract Diseases; D017386:Sequence Homology, Amino Acid; D013296:Streptococcus pneumoniae / Q000254:growth & development / Q000472:pathogenicity*; D014774:Virulence / Q000502:physiology*
D008074:Lipoproteins