title: Biosynthesis of butirosin in Bacillus circulans NRRL B3312: identification by sequence analysis and insertional mutagenesis of the butB gene involved in antibiotic production.
abstract: As an approach to an analysis of the biosynthesis of the aminoglycoside antibiotic butirosin (But), we investigated the chromosomal regions flanking the ButR gene (aphA4/butA) of Bacillus circulans NRRL-B3312, and have identified, by nucleotide sequence analysis, a large open reading frame (ORF; ButB) upstream from the ButR gene. Hybridization was detected between butB and chromosomal DNA from other Bacillaceae that produce But-like compounds (but not from non-producers). Interruption of this sequence by insertion of an erythromycin-resistance-encoding gene (erm) at either of two distinct sites eliminated the production (biosynthesis or export) of But, thus indicating a role for butB in antibiotic production. Gene butB is transcribed in the same direction as butA and encodes a protein of 1616 amino acid (aa) residues with a 30-aa N-terminal signal peptide. Comparison of the sequence for the translation product (ButB) with the aa compositions and sequences of known bacterial surface proteins, such as S-layer proteins, suggests that this protein is cell-wall associated. It is proposed that ButB plays a role in the export of But from the producing organism.
authors.affiliation: Unité de Génie Microbiologique, Institut Pasteur, Paris, France.
authors.forename: E
authors.initials: E
authors.lastname: Aubert-Pivert
authors.forename: J
authors.initials: J
authors.lastname: Davies
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002076:Butirosin Sulfate / Q000096:biosynthesis*; D002352:Carrier Proteins / Q000235:genetics*; D002473:Cell Wall / Q000737:chemistry; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial; D005798:Genes, Bacterial; D008565:Membrane Proteins / Q000235:genetics; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; C089405:ButB protein, Bacillus circulans; D002352:Carrier Proteins; D004269:DNA, Bacterial; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D012333:RNA, Messenger; D002076:Butirosin Sulfate