Cloning and Nucleotide Sequence of Streptococcus pneumoniae ftsH Gene

The gene ftsH encodes a membrane-bound and ATP-dependent protease that is involved in a variety of cellular functions including heat-shock and stress response. Streptococcus pneumoniae DNA encompassing most part of the ftsH gene was cloned in Escherichia coli and sequenced. Due to the unsuccessful cloning as seen in other pneumococcal promoters, the 5'-end of the gene including the upstream promoter region was amplified by inverse polymerase chain reaction and then sequenced by cyclic sequencing. The amino acid sequence that is deduced from the 1,959 bp-long ftsH gene is very similar to FtsH of several gram-positive bacteria and E. coli within the region responsible for the AAA (ATPase associated with diverse cellular activities) function. Except for the N-terminal domain that contains a short extracellular region between two mernbrane-spanning segments, pneumococcal FtsH shows striking sequence similarity to that of a closely related species Lactococcus lactis within the conserved cytoplasmic domain where two ATP-binding motifs, the AAA Signature motif, and a zinc-binding motif are found.

Cloning and Characterization of the Differentially Expressed Genes in Streptococcus pneumoniae

In spite of the extensive use of antibiotics over several decades, Streptococcus pneumoniae still remains as one of the most serious human bacterial pathogens. In order to clone the pneumococcal genes whose expression is induced when pneumococcus causes infection in mice, S. pneumoniae strain ATCC 6303 was subcultured on blood agar plates (BAP) ten times to reduce the virulence first, and then passaged through BALB/c mice three times to restore the virulence. Subtractive hybridization was performed using the total RNA preparations isolated from BAP-cultured and mouse-passaged strains. Complementary DNAs corresponding to any mRNA species that were differentially expressed in the mouse- passaged strain were used as the probes to screen the genomic library of pneumococcus. Positive recombinants were selected and sequenced partially to identify the genes located within the cloned DNA. GenBank search of the sequence data has identified several genes including two heat shock genes (dnaK and dnap, a transposase-encoding gene, and a sequence which is very homologous to that of the ftsH gene.

Four Cases of Kartagener's Syndrome / 결핵

Kartagener's syndrome is an autosomaly inherited recessive condition characterized by situs inversus, bronchiectasis, and chronic sinusitis. And recently it was recognized as a subclass of dyskinetic cilia syndrome which caused by a defect in mucociliary transport owing to immotile or dyskinetic beating of cilia. Electron microsopy of cilia from sperm tails, nasal and bronchial epithelium of patients reveals the partial or complete absence of dynein arms. Our four patients were diagnosed as a Kartagener's syndrome by classic triad. We carried out electron microscopy of cilia of the nasal mucosa. And many other tests were done. One patient had squamous cell carcinoma of the lung, and another one patient revealed features of adult respiratory distress syndrome at admission. All patients improved with conservative therapy such as physiotherapy, bronchodilater, antibiotics except one patient who mechanical ventilation was required. A brief review of literature was made.