Open AccessRole of the unique, non-essential phosphatidylglycerol::prolipoprotein diacylglyceryl transferase (Lgt) in Corynebacterium glutamicum
Author(s) -
Nathalie Dautin,
Manuela Argentini,
Niloofar Mohiman,
C Labarre,
David Cornu,
Laïla Sago,
Mohamed Chami,
Christiane Dietrich,
Célia de Sousa d’Auria,
Christine Houssin,
Muriel Masi,
C. Salmeron,
Nicolas Bayan
Publication year - 2020
Publication title -
microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 179
eISSN - 1465-2080
pISSN - 1350-0872
DOI - 10.1099/mic.0.000937
Subject(s) - corynebacterium glutamicum , phosphatidylglycerol , signal peptide , biochemistry , biology , signal peptidase , acyl group , transferase , peptide , peptide sequence , membrane , chemistry , phospholipid , enzyme , phosphatidylcholine , gene , alkyl , organic chemistry
Bacterial lipoproteins are secreted proteins that are post-translationally lipidated. Following synthesis, preprolipoproteins are transported through the cytoplasmic membrane via the Sec or Tat translocon. As they exit the transport machinery, they are recognized by a phosphatidylglycerol::prolipoprotein diacylglyceryl transferase (Lgt), which converts them to prolipoproteins by adding a diacylglyceryl group to the sulfhydryl side chain of the invariant Cys +1 residue. Lipoprotein signal peptidase (LspA or signal peptidase II) subsequently cleaves the signal peptide, liberating the α-amino group of Cys +1 , which can eventually be further modified. Here, we identified the lgt and lspA genes from Corynebacterium glutamicum and found that they are unique but not essential. We found that Lgt is necessary for the acylation and membrane anchoring of two model lipoproteins expressed in this species: MusE, a C. glutamicum maltose-binding lipoprotein, and LppX, a Mycobacterium tuberculosis lipoprotein. However, Lgt is not required for these proteins’ signal peptide cleavage, or for LppX glycosylation. Taken together, these data show that in C. glutamicum the association of some lipoproteins with membranes through the covalent attachment of a lipid moiety is not essential for further post-translational modification.