TatC is a specificity determinant for protein secretion via the twin-arginine translocation pathway.
The recent discovery of a ubiquitous translocation pathway, specifically required for proteins with a twin-arginine motif in their signal peptide, has focused interest on its membrane-bound components, one of which is known as TatC. Unlike most organisms of which the genome has been sequenced completely, the Gram-positive eubacterium Bacillus subtilis contains two tatC-like genes denoted tatCd and tatCy. The corresponding TatCd and TatCy proteins have the potential to be involved in the translocation of 27 proteins with putative twin-arginine signal peptides of which approximately 6-14 are likely to be secreted into the growth medium. Using a proteomic approach, we show that PhoD of B. subtilis, a phosphodiesterase belonging to a novel protein family of which all known members are synthesized with typical twin-arginine signal peptides, is secreted via the twin-arginine translocation pathway. Strikingly, TatCd is of major importance for the secretion of PhoD, whereas TatCy is not required for this process. Thus, TatC appears to be a specificity determinant for protein secretion via the Tat pathway. Based on our observations, we hypothesize that the TatC-determined pathway specificity is based on specific interactions between TatC-like proteins and other pathway components, such as TatA, of which three paralogues are present in B. subtilis.
Jongbloed
J D
JD
Department of Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, Kerklaan 30, 9751 NN Haren, The Netherlands.
Martin
U
U
Antelmann
H
H
Hecker
M
M
Tjalsma
H
H
Venema
G
G
Bron
S
S
van Dijl
J M
JM
Müller
J
J
D000595:Amino Acid Sequence; D001120:Arginine; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D001692:Biological Transport; D008969:Molecular Sequence Data; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry / Q000378:metabolism*; D017510:Protein Folding
D001426:Bacterial Proteins; D001120:Arginine; D010727:Phosphoric Diester Hydrolases