title: The structure of bypass of forespore C, an intercompartmental signaling factor during sporulation in Bacillus.
abstract: Sporulation in Bacillus subtilis begins with an asymmetric cell division giving rise to smaller forespore and larger mother cell compartments. Different programs of gene expression are subsequently directed by compartment-specific RNA polymerase sigma-factors. In the final stages, spore coat proteins are synthesized in the mother cell under the control of RNA polymerase containing sigma(K), (Esigma(K)). sigma(K) is synthesized as an inactive zymogen, pro-sigma(K), which is activated by proteolytic cleavage. Processing of pro-sigma(K) is performed by SpoIVFB, a metalloprotease that resides in a complex with SpoIVFA and bypass of forespore (Bof)A in the outer forespore membrane. Ensuring coordination of events taking place in the two compartments, pro-sigma(K) processing in the mother cell is delayed until appropriate signals are received from the forespore. Cell-cell signaling is mediated by SpoIVB and BofC, which are expressed in the forespore and secreted to the intercompartmental space where they regulate pro-sigma(K) processing by mechanisms that are not yet fully understood. Here we present the three-dimensional structure of BofC determined by solution state NMR. BofC is a monomer made up of two domains. The N-terminal domain, containing a four-stranded beta-sheet onto one face of which an alpha-helix is packed, closely resembles the third immunoglobulin-binding domain of protein G from Streptococcus. The C-terminal domain contains a three-stranded beta-sheet and three alpha-helices in a novel domain topology. The sequence connecting the domains contains a conserved DISP motif to which mutations that affect BofC activity map. Possible roles for BofC in the sigma(K) checkpoint are discussed in the light of sequence and structure comparisons.
authors.affiliation: Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, United Kingdom.
authors.forename: Hayley M
authors.initials: HM
authors.lastname: Patterson
authors.forename: James A
authors.initials: JA
authors.lastname: Brannigan
authors.forename: Simon M
authors.initials: SM
authors.lastname: Cutting
authors.forename: Keith S
authors.initials: KS
authors.lastname: Wilson
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Wilkinson
authors.forename: Eiso
authors.initials: E
authors.lastname: Ab
authors.forename: Tammo
authors.initials: T
authors.lastname: Diercks
authors.forename: Rob N
authors.initials: RN
authors.lastname: de Jong
authors.forename: Vincent
authors.initials: V
authors.lastname: Truffault
authors.forename: Gert E
authors.initials: GE
authors.lastname: Folkers
authors.forename: Robert
authors.initials: R
authors.lastname: Kaptein
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000502:physiology*; D002450:Cell Communication; D002462:Cell Membrane / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D009682:Magnetic Resonance Spectroscopy; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D021241:Spectrometry, Mass, Electrospray Ionization; D013171:Spores, Bacterial / Q000378:metabolism / Q000502:physiology*; D014157:Transcription Factors / Q000737:chemistry / Q000502:physiology*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C104572:BofC protein, Bacillus subtilis; D011994:Recombinant Proteins; D014157:Transcription Factors; D012321:DNA-Directed RNA Polymerases