title: Mycoloyltransferases: A large and major family of enzymes shaping the cell envelope of Corynebacteriales.
abstract: Mycobacterium and Corynebacterium are important genera of the Corynebacteriales order, the members of which are characterized by an atypical diderm cell envelope. Indeed the cytoplasmic membrane of these bacteria is surrounded by a thick mycolic acid-arabinogalactan-peptidoglycan (mAGP) covalent polymer. The mycolic acid-containing part of this complex associates with other lipids (mainly trehalose monomycolate (TMM) and trehalose dimycolate (TDM)) to form an outer membrane. The metabolism of mycolates in the cell envelope is governed by esterases called mycoloyltransferases that catalyze the transfer of mycoloyl chains from TMM to another TMM molecule or to other acceptors such as the terminal arabinoses of arabinogalactan or specific polypeptides. In this review we present an overview of this family of Corynebacteriales enzymes, starting with their expression, localization, structure and activity to finally discuss their putative functions in the cell. In addition, we show that Corynebacteriales possess multiple mycoloyltransferases encoding genes in their genome. The reason for this multiplicity is not known, as their function in mycolates biogenesis appear to be only partially redundant. It is thus possible that, in some species living in specific environments, some mycoloyltransferases have evolved to gain some new functions. In any case, the few characterized mycoloyltransferases are very important for the bacterial physiology and are also involved in adaptation in the host where they constitute major secreted antigens. Although not discussed in this review, all these functions make them interesting targets for the discovery of new antibiotics and promising vaccines candidates. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo.
authors.affiliation: Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Dautin
authors.affiliation: Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Célia
authors.initials: C
authors.lastname: de Sousa-d'Auria
authors.affiliation: Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Constantinesco-Becker
authors.affiliation: Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Labarre
authors.affiliation: Cell Biology of Archaea, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Oberto
authors.affiliation: Function and Architecture of Macromolecular Assemblies, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Ines
authors.initials: I
authors.lastname: Li de la Sierra-Gallay
authors.affiliation: Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Christiane
authors.initials: C
authors.lastname: Dietrich
authors.affiliation: Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France; Faculty of Sciences, Department of Life and Earth Sciences, Holy Spirit University of Kaslik (USEK), Kaslik, B.P. 446, Jounieh, Lebanon.
authors.forename: Hanane
authors.initials: H
authors.lastname: Issa
authors.affiliation: Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France. Electronic address: christine.houssin@i2bc.paris-saclay.fr.
authors.forename: Christine
authors.initials: C
authors.lastname: Houssin
authors.affiliation: Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France. Electronic address: nicolas.bayan@i2bc.paris-saclay.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bayan
mesh_terms: D000217:Acyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology*; D003352:Corynebacterium / Q000201:enzymology* / Q000235:genetics; D005810:Multigene Family; D009171:Mycolic Acids / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D009171:Mycolic Acids; D000217:Acyltransferases
keywords: Antigen 85; Esterase; Fibronectin-binding protein; Mycobacterium; Mycolyltransferases; Mycomembrane