To obtain a new polynucleotide for screening an antibiotic activity and treatment, diagnosis, etc., of infection of a bacterium of the genus Streptococcus, having high identity to nucleic acid encoding ffh(fifty-four homologue) polypeptide having a specific amino acid sequence.
This new isolated polynucleotide comprises a polynucleotide having at least 90% identity to a polynucleotide encoding a polypeptide containing an amino acid sequence of the formula, a polynucleotide, etc., having at least 70% identity to a polynucleotide encoding the same mature polypeptide as a polypeptide expressed by ffh gene contained in Staphylococcus aureus of deposited strains and the polynucleotide is useful for screening of antibacterial compound and treatment, diagnosis, etc., of Staphylococcus pneumoniae. The polynucleotide is obtained by probing chromosomal DNA library of Staphylococcus pneumoniae with a labeled oligonucleotide derived from a partial sequence.
