The secretory S complex in Bacillus subtilis is identified as pyruvate dehydrogenase.
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.
Hemilä
H
H
Institute of Biotechnology, Helsinki.
Palva
A
A
Paulin
L
L
Adler
L
L
Arvidson
S
S
Palva
I
I
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
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011768:Pyruvate Dehydrogenase Complex