The Pseudomonas aeruginosa patatin-like protein PlpD is the archetype of a novel Type V secretion system

Environ Microbiol. 2010 Jun;12(6):1498-512. doi: 10.1111/j.1462-2920.2010.02174.x. Epub 2010 Feb 23.

Abstract

We discovered a novel secreted protein by Pseudomonas aeruginosa, PlpD, as a member of the bacterial lipolytic enzyme family of patatin-like proteins (PLPs). PlpD is synthesized as a single molecule consisting of a secreted domain fused to a transporter domain. The N-terminus of PlpD includes a classical signal peptide followed by the four PLP conserved blocks that account for its lipase activity. The C-terminus consists of a POTRA (polypeptide transport-associated) motif preceding a putative 16-stranded beta-barrel similar to those of TpsB transporters of Type Vb secretion system. We showed that the C-terminus remains inserted into the outer membrane while the patatin moiety is secreted. The association between a TpsB component and a passenger protein is a unique hybrid organization that we propose to classify as Type Vd. More than 200 PlpD orthologues exist among pathogenic and environmental bacteria, which suggests that bacteria secrete numerous PLPs using this newly defined mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / classification
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism*
  • Carboxylic Ester Hydrolases / chemistry
  • Carboxylic Ester Hydrolases / classification
  • Carboxylic Ester Hydrolases / genetics*
  • Carboxylic Ester Hydrolases / metabolism*
  • Exocytosis / physiology*
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Plant Proteins / chemistry
  • Plant Proteins / classification
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism*
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Pseudomonas aeruginosa* / enzymology
  • Pseudomonas aeruginosa* / physiology
  • Sequence Alignment

Substances

  • Bacterial Proteins
  • Plant Proteins
  • patatin protein, Solanum tuberosum
  • Carboxylic Ester Hydrolases