Characterization of bofA, a gene involved in intercompartmental regulation of pro-sigma K processing during sporulation in Bacillus subtilis.
Sporulating cells of the gram-positive bacterium Bacillus subtilis are partitioned into two cellular compartments called the mother cell and the forespore. Gene expression in the mother cell and the forespore is regulated differentially by the compartment-specific transcription factors sigma K and sigma G, respectively. Gene expression between the two compartments is also coordinated by a signal transduction pathway that couples the activation of sigma K (by processing of its inactive precursor pro-sigma K) in the mother cell to sigma G-directed gene expression in the forespore. To dissect the signal transduction pathway genetically, we previously isolated bypass of forespore mutations at loci called bofA and bofB that relieve the dependence of pro-sigma K processing on the action of sigma G. bofB mutations were previously shown to be allelic to the two-cistron sporulation operon spoIVF, which encodes the pro-sigma K-processing enzyme or its regulator. We now report that bofA mutations are located in a small open reading frame of 87 codons that encodes a putative integral membrane protein with three potential membrane-spanning domains. The possibility is discussed that BofA and the SpoIVF proteins form a heteromeric complex in the mother cell membrane that surrounds the forespore and that this complex mediates the intercompartmental coupling of pro-sigma K processing to events in the forespore.
Ricca
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Department of Cellular and Developmental Biology, Harvard University, Cambridge, Massachusetts 02138.
Cutting
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Losick
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D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D004252:DNA Mutational Analysis; D005798:Genes, Bacterial / Q000235:genetics*; D005808:Genes, Recessive; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011487:Protein Conformation; D011498:Protein Precursors / Q000235:genetics; D011499:Protein Processing, Post-Translational; D012689:Sequence Homology, Nucleic Acid; D012808:Sigma Factor / Q000235:genetics; D013171:Spores, Bacterial / Q000235:genetics; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D008565:Membrane Proteins; D011498:Protein Precursors; D012808:Sigma Factor; C074423:bofA protein, Bacillus subtilis