The pilE gene product of Pseudomonas aeruginosa, required for pilus biogenesis, shares amino acid sequence identity with the N-termini of type 4 prepilin proteins

Mol Microbiol. 1994 Sep;13(6):973-85. doi: 10.1111/j.1365-2958.1994.tb00489.x.


A new locus required for type 4 pilus biogenesis by Pseudomonas aeruginosa has been identified. A pilE mutant, designated MJ-6, was broadly resistant to pili-specific phages and unable to translocate across solid surfaces by the pilus-dependent mechanism of twitching motility (Twt-). Immunoblot analysis demonstrated that MJ-6 was devoid of pili (Pil-) but was unaffected in the production of unassembled pilin pools. Genetic studies aimed at localizing the pilE mutation on the P. aeruginosa PAO chromosome demonstrated a strong co-linkage between MJ-6 phage resistance and the proB marker located at 71 min. Cloning of the pilE gene was facilitated by the isolation and identification of a pro(B+)-containing plasmid from a PAO1 cosmid library. Upon introduction of the PAO1 proB+ cosmid clone into MJ-6, sensitivity to pili-specific phage, twitching motility and pilus production were restored. The nucleotide sequence of a 1 kb EcoRV-ClaI fragment containing the pilE region revealed a single complete open reading frame with characteristic P. aeruginosa codon bias. PilE, a protein with a molecular weight of 15,278, showed significant sequence identity to the pilin precursors of P. aeruginosa and to other type 4 prepilin proteins. The region of highest homology was localized to the N-terminal 40 amino acid residues. The putative PilE N-terminus contained a seven-residue basic leader sequence followed by a consensus cleavage site for prepilin peptidase and a largely hydrophobic region which contained tyrosine residues (Tyr-24 and Tyr-27) previously implicated in maintaining pilin subunit-subunit interactions. The requirement of PilE in pilus biogenesis was confirmed by demonstrating that chromosomal pilE insertion mutants were pilus- and twitching-motility deficient.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Outer Membrane Proteins / chemistry*
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / metabolism
  • Base Sequence
  • Chromosome Mapping
  • Chromosomes, Bacterial
  • Consensus Sequence
  • Endopeptidases*
  • Fimbriae Proteins
  • Fimbriae, Bacterial / metabolism*
  • Genes, Bacterial
  • Genetic Complementation Test
  • Molecular Sequence Data
  • Protein Precursors / chemistry*
  • Pseudomonas aeruginosa / genetics*
  • Sequence Alignment
  • Sequence Homology, Amino Acid*


  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • Protein Precursors
  • pilE protein, Neisseria gonorrhoeae
  • Fimbriae Proteins
  • Endopeptidases
  • prepilin peptidase protein, Bacteria

Associated data

  • GENBANK/U02552