Open AccessNovel FNR homologues identified in four representative oral facultative anaerobes: Capnocytophaga ochracea, Capnocytophaga sputigena, Haemophilus aphrophilus , and Actinobacillus actinomycetemcomitans
Author(s) -
Hattori Takako,
Takahashi Kojiro,
Nakanishi Tohru,
Ohta Hiroyuki,
Fukuixa Kazuhiro,
Taniguchixa Shigehiko,
Takigawa Masaharu
Publication year - 1996
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1996.tb08108.x
Subject(s) - microbiology and biotechnology , actinobacillus , capnocytophaga , operon , biology , pasteurellaceae , haemophilus , escherichia coli , bacteria , haemophilus influenzae , biochemistry , gene , genetics , antibiotics
Based upon DNA sequence data and positive immunochemical reactivity of expressed protein, novel homologues of the FNR family were identified in four representative oral facultative anaerobes: Capnocytophaga ochracea, Capnocytophaga sputigena, Haemophilus aphrophilus , and Actinobacillus actinomycetemcomitans . The similarity to E. coli FNR and to HlyX (itself 71% similar to E. coli FNR, while regulating expression of hemolysin operon in Actinobacillus pleuropneumoniae ) was estimated from the deduced partial amino acid sequence to be, in the above order of tested species, 98, 98, 86, and 85%, and 75, 75, 88, and 88%, respectively. The phylogenetic relatedness indicates a rather closer link of HlyX to the FNR homologues from both pathogens, H. aphrophilus and A. actinomycetemcomitans . The possibility that the A. actinomycetemcomitans FNR homologue functions as a redox‐sensing transcriptional factor to regulate, in addition to anaerobic respiration, microaerobic expression of the leukotoxin operon ( ltx gene) is suggested.