In the absence of Lgt, lipoproteins are shed from Streptococcus uberis independently of Lsp

E L Denham, P N Ward, James A. Leigh

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The role of lipoprotein diacylglyceryl transferase (Lgt) and lipoprotein signal peptidase (Lsp) responsible for processing lipoproteins was investigated in Streptococcus uberis, a common cause of bovine mastitis. In the absence of Lgt, three lipoproteins [MtuA (SUB0473), Hap (SUB1625) and an extracellular solute-binding protein (SUB0365)] were detected in extracellular locations. All were shown by Edman degradation analysis to be cleaved on the carboxy side of the LXXC lipobox. Detection of MtuA, a lipoprotein shown previously to be essential for infectivity and virulence, was used as a surrogate lipoprotein marker to locate and assess processing of lipoproteins. The absence of Lgt did not prevent location of MtuA to the cell membrane, its location in the wild-type strain but, in contrast to the situation with wild-type, did result in a widespread location of this protein. In the absence of both Lgt and Lsp, MtuA was similarly released from the bacterial cell. In such strains, however, the cell-associated MtuA represented the full-length gene product, indicating that Lsp was able to cleave non-lipidated (lipo)proteins but was not responsible for their release from this bacterium.

Original languageEnglish
Pages (from-to)134-141
Number of pages8
JournalMicrobiology
Volume155
Issue number1
Early online date1 Jan 2009
DOIs
Publication statusPublished - 2009

Keywords

  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins/chemistry
  • Cattle
  • Female
  • Lipoproteins/chemistry
  • Mastitis, Bovine/microbiology
  • Membrane Proteins/metabolism
  • Molecular Sequence Data
  • Mutation
  • Serine Endopeptidases/metabolism
  • Streptococcus/classification
  • Subcellular Fractions/metabolism
  • Transferases/genetics

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