title: The secretory S complex in Bacillus subtilis is identified as pyruvate dehydrogenase.
abstract: We have cloned the operon for the Bacillus subtilis S complex, which has been suggested to be a component of the protein secretion machinery. The S-complex operon was found to encode 4 proteins, which were identified as subunits of pyruvate dehydrogenase (PDH). The Staphylococcus aureus membrane-bound ribosome protein (MBRP) complex has been considered to be a counterpart of the B. subtilis S complex. Here, we sequenced a fragment of the MBRP operon encoding the C-terminal part of E1 beta, the entire E2 and the N-terminal part of the E3 subunit of PDH, thus conclusively confirming the PDH identity of the MBRP complex as well. It appeared unlikely that PDH could be a primary component in protein secretion, thus disproving the previous hypothesis of the role of the S complex. However, attachment of the S complex (PDH) to the membrane and ribosomes may produce a biologically significant interaction.
authors.affiliation: Institute of Biotechnology, Helsinki.
authors.forename: H
authors.initials: H
authors.lastname: Hemilä
authors.forename: A
authors.initials: A
authors.lastname: Palva
authors.forename: L
authors.initials: L
authors.lastname: Paulin
authors.forename: L
authors.initials: L
authors.lastname: Adler
authors.forename: S
authors.initials: S
authors.lastname: Arvidson
authors.forename: I
authors.initials: I
authors.lastname: Palva
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence / Q000235:genetics; D015153:Blotting, Western; D004269:DNA, Bacterial / Q000235:genetics; D066298:In Vitro Techniques; D009876:Operon / Q000235:genetics; D011768:Pyruvate Dehydrogenase Complex / Q000235:genetics*; D013211:Staphylococcus aureus / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011768:Pyruvate Dehydrogenase Complex