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Molecular basis of the optochin‐sensitive phenotype of pneumococcus: characterization of the genes encoding the F 0 complex of the Streptococcus pneumoniae Streptococcus oralis H + ‐ATPases
Author(s) -
Fenoll Asunción,
Muñoz Rosario,
Garcia Ernesto,
Campa Adela G.
Publication year - 1994
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.1365-2958.1994.tb01045.x
Subject(s) - streptococcus oralis , biology , streptococcus pneumoniae , gene , microbiology and biotechnology , genetics , streptococcaceae , streptococcus , nucleic acid sequence , streptococcus mitis , bacteria
Summary The gene responsible for the optochin‐sensitive (Opt S ) phenotype of Streptococcus pneumoniae has been characterized. Sequence comparisons indicated that the genes involved encoded the subunits of the F 0 complex of an H + ‐ATPase. Sequence analysis and transformation experiments showed that the atpC gene is responsible for the optochin‐sensitive resistant (Opt S /Opt R ) phenotype. Our results also show that natural as well as laboratory Opt R isolates have arisen by point mutations that produce different amino acid changes at positions 48, 49 or 50 of the ATPase c subunit. The nucleotide sequence of the F F 0 complex of the Streptococcus oralis ATPase has also been determined. In addition, comparison of the sequence of the atpCAB genes of S. pneumoniae R6 (Opt S ) and M222 (an Opt R strain produced by inter‐species recombination between pneumococcus and S. oralis) , and S. oralis revealed that, in M222, an interchange of atpC and atpA had occurred. We also demonstrate that optochin specifically inhibited the membrane‐bound ATPase activity of the S. pneumoniae wild‐type (Opt S ) strains, and found a 100‐fold difference between Opt S and Opt R strains, both in growth inhibition and in membrane ATPase resistance.