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Lipid modification of prelipoproteins is dispensable for growth but essential for efficient protein secretion in Bacillus subtilis : characterization of the lgt gene
Author(s) -
Leskelä Soile,
Wahlström Eva,
Kontinen Vesa P.,
Sarvas Matti
Publication year - 1999
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.1999.01247.x
Subject(s) - bacillus subtilis , biology , diacylglycerol kinase , mutant , secretion , biochemistry , bacillaceae , signal peptide , gene , enzyme , bacteria , peptide sequence , genetics , protein kinase c
We have identified and characterized the lgt gene of Bacillus subtilis . The prelipoprotein diacylglycerol transferase enzyme (Lgt) catalyses the first reaction in lipomodification of bacterial lipoproteins. Inactivation of lgt in B. subtilis by a nonsense mutation ( prs‐11 mutation) or by disruption was shown here to abolish lipomodification of prelipoproteins completely, as well as the cleavage of signal peptide. However, unlike in Gram‐negative bacteria, the lgt mutants of B. subtilis were fully viable. In agreement with this observation, studies of two lipoproteins, PrsA and BlaP, indicated that non‐lipomodified precursors of these proteins were functional and translocated across the cytoplasmic membrane. However, there was release of both precursors from cells, resulting in a reduced level of the cell‐bound form. We have shown that the reduced level of the PrsA lipoprotein, a foldase involved in protein secretion, caused impaired protein secretion, a prominent phenotype of lgt mutants. There was no indication that non‐lipomodified PrsA displayed reduced activity.