title: Characterization of a ComE3 homologue essential for DNA transformation in Helicobacter pylori.
abstract: To find genes involved in natural competence in Helicobacter pylori, we used a bioinformatics database search and found two transformation-related open reading frames (ORFs): a comE3 homologue (HP1361 ORF) of Bacillus subtilis and a comL homologue (HP1378 ORF) of Neisseria gonorrhoeae. We failed to obtain an HP1378 ORF knockout mutant, while an HP1361 ORF knockout mutant was obtained by transposon shuttle mutagenesis. The DNA transformation abilities of both natural transformation and electroporation were severely impaired (frequency, <10(-9)) in the HP1361(-) mutant. Complementation with a pHel2 vector carrying the HP1361 ORF restored the capabilities of natural competence (to a frequency of 4.21 x 10(-7)) and electroporation (to 3.62 x 10(-7)). The HP1361(-) mutant showed impairment in DNA binding and uptake. The results suggest that HP1361 is a comE3 homologue and is required for DNA binding and uptake during DNA transformation.
authors.affiliation: Graduate Institute of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Yu-Ching
authors.initials: YC
authors.lastname: Yeh
authors.forename: Tzu-Lung
authors.initials: TL
authors.lastname: Lin
authors.forename: Kai-Chih
authors.initials: KC
authors.lastname: Chang
authors.forename: Jin-Town
authors.initials: JT
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D030561:Databases, Nucleic Acid; D017353:Gene Deletion; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D016480:Helicobacter pylori / Q000235:genetics* / Q000378:metabolism; D008074:Lipoproteins / Q000235:genetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D016366:Open Reading Frames; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic; D017386:Sequence Homology, Amino Acid; D014170:Transformation, Genetic
chemical_list: D001426:Bacterial Proteins; C103179:ComE protein, Streptococcus pneumoniae; D004269:DNA, Bacterial; D008074:Lipoproteins; C101255:comL protein, Neisseria gonorrhoeae