title: The involvement of SelB in the expression of cytotoxic necrotizing factor 1 in Escherichia coli.
abstract: Cytotoxic necrotizing factor 1 (CNF1) plays an important role in meningitis-causing Escherichia coli. Mini-Tn5 mutagenesis of meningitis-causing E. coli revealed that transposon mutants of selA and selB genes failed to express CNF1. We subsequently showed that SelB and selenocysteine, however, are not essential for the expression of CNF1, but the deletion of 47 amino acids of SelB at its C terminus has a dominant negative effect on CNF1 expression at the translational level. Bioinformatic analysis of the mRNA of cnf1 predicted two putative selenocysteine incorporation sequence (SECIS) elements, but we failed to detect any selenocysteine in CNF1 protein. These findings suggest that SelB is involved in translational regulation of CNF1 expression but without incorporation of selenocysteine in CNF1 protein.
authors.affiliation: Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Yu
authors.forename: Kwang Sik
authors.initials: KS
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000502:physiology*; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000235:genetics; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D020814:Meningitis, Escherichia coli; D014176:Protein Biosynthesis; D017279:Selenocysteine / Q000378:metabolism; D017384:Sequence Deletion
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D029968:Escherichia coli Proteins; C061878:SelB protein, Bacteria; D017279:Selenocysteine; C060296:cytotoxic necrotizing factor type 1