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The product of the pilQ gene is essential for the biogenesis of type IV pili in Neisseria gonorrhoeae
Author(s) -
Drake Sandra L.,
Koomey Michael
Publication year - 1995
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1995.18050975.x
Subject(s) - pilus , biology , mutant , neisseria gonorrhoeae , gene , gene product , bacterial outer membrane , microbiology and biotechnology , pilin , genetics , gene expression , escherichia coli
The product of the Neisseria gonorrhoeae omc gene possesses regions homologous to those found in members of a protein superfamily that are associated with the translocation of proteins and DNA‐protein complexes across the outer membrane. Amongst its protein homologues, Omc has higher overall homology to PilQ, which is required for type IV pilus expression in Pseudomonas aeruginosa , and OrfE, which is required for sequence‐specific DNA uptake by Haemophilus influenzae . The function of Omc, however, is unknown and gonococcal omc mutants have not been described. We constructed gonococcal mutants expressing truncated forms of the protein, and found that these mutants are severely defective for both pilus expression and competence for natural transformation. To be consistent with pre‐existing pilus gene nomenclature, we have redesignated the gene pilQ instead of omc , and its product, PilQ instead of Omc. The MS11 gene was sequenced and found to differ from the DNA sequence reported for that of another gonococcal strain; these differences were associated with a repeated DNA element, suggesting a genetic basis for structural variation in PilQ. The results also show that PilQ − mutants are distinct from previously described gonococcal pilus‐assembly mutants and P. aeruginosa PilQ − mutants by virtue of their expression of rare pilus filaments. Taking these data into account, PilQ is proposed to function in the terminal steps of organelle biogenesis by acting as a pilus channel or pore.