The phosphatidic acid pathway enzyme PlsX plays both catalytic and channeling roles in bacterial phospholipid synthesis

Author(s)

Sastre, Diego E. ^{[1, 2]} ; Pulschen, Andre A. ^[1] ; Basso, Luis G. M. ^[3] ; Pariente, Jhonathan S. Benites ^[1] ; Marques Netto, Caterina G. C. ^[4] ; Machinandiarena, Federico ^{[5, 6, 7]} ; Albanesi, Daniela ^{[5, 6, 7]} ; Navarro, Marcos V. A. S. ^[2] ; de Mendoza, Diego ^{[5, 6, 7]} ; Gueiros-Filho, Frederico J. ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Bioquim, Inst Quim, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Dept Biofis Mol, Inst Fis Sao Carlos, Grp Biofis Mol Sergio Mascarenhas, BR-13560970 Sao Carlos, SP - Brazil

^[3] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Fis, BR-14040901 Ribeirao Preto, SP - Brazil

^[4] Univ Fed Sao Carlos UFSCar, Dept Quim, BR-13565905 Sao Carlos, SP - Brazil

^[5] Consejo Nacl Invest Cient & Tecn, Buenos Aires, DF - Argentina

^[6] Univ Nacl Rosario, CONICET, Inst Biol Mol & Celular Rosario IBR, S2002LRK, Rosario, Santa Fe - Argentina

^[7] Univ Nacl Rosario, Dept Microbiol, Fac Ciencias Bioquim & Farmaceut, S2002LRK, Rosario, Santa Fe - Argentina

• Document type: Journal article
• Source: Journal of Biological Chemistry; v. 295, n. 7, p. 2148-2159, FEB 14 2020.
• Web of Science Citations: 1

Abstract

PlsX is the first enzyme in the pathway that produces phosphatidic acid in Gram-positive bacteria. It makes acylphosphate from acyl-acyl carrier protein (acyl-ACP) and is also involved in coordinating phospholipid and fatty acid biosyntheses. PlsX is a peripheral membrane enzyme in Bacillus subtilis, but how it associates with the membrane remains largely unknown. In the present study, using fluorescence microscopy, liposome sedimentation, differential scanning calorimetry, and acyltransferase assays, we determined that PlsX binds directly to lipid bilayers and identified its membrane anchoring moiety, consisting of a hydrophobic loop located at the tip of two amphipathic dimerization helices. To establish the role of the membrane association of PlsX in acylphosphate synthesis and in the flux through the phosphatidic acid pathway, we then created mutations and gene fusions that prevent PlsX's interaction with the membrane. Interestingly, phospholipid synthesis was severely hampered in cells in which PlsX was detached from the membrane, and results from metabolic labeling indicated that these cells accumulated free fatty acids. Because the same mutations did not affect PlsX transacylase activity, we conclude that membrane association is required for the proper delivery of PlsX's product to PlsY, the next enzyme in the phosphatidic acid pathway. We conclude that PlsX plays a dual role in phospholipid synthesis, acting both as a catalyst and as a chaperone protein that mediates substrate channeling into the pathway. (AU)

• FAPESP's process: 14/00206-0 - Structure and function of SARS-CoV spike glycoprotein fusion peptides
• Grantee: Luís Guilherme Mansor Basso
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 15/21583-0 - Development of new antibiotics against super-resistant Staphylococcus aureus strains: identification and characterization of inhibitors of the enzyme Diadenylate cyclase
• Grantee: Marcos Vicente de Albuquerque Salles Navarro
• Support type: Regular Research Grants
• FAPESP's process: 14/13411-1 - Study of acyltransferases required for the synthesis of membrane phospholipids in Gram-positive bacteria: an attractive target for antibacterial drug discovery
• Grantee: Diego Emiliano Sastre
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 16/05203-5 - HOW DO BACTERIA COORDINATE MEMBRANE BIOGENESIS WITH CELL GROWTH AND DIVISION?
• Grantee: Frederico José Gueiros Filho
• Support type: Regular Research Grants