Mycoloyltransferases: A large and major family of enzymes shaping the cell envelope of Corynebacteriales

• Published in: Biochimica et biophysica acta. General subjects Vol. 1861; no. 1; pp. 3581 - 3592
• Main Authors: Dautin, Nathalie, de Sousa-d'Auria, Célia, Constantinesco-Becker, Florence, Labarre, Cécile, Oberto, Jacques, Li de la Sierra-Gallay, Ines, Dietrich, Christiane, Issa, Hanane, Houssin, Christine, Bayan, Nicolas
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2017; Elsevier
• Subjects: Acyltransferases - chemistry; Acyltransferases - genetics; Acyltransferases - metabolism; antibiotics; Antigen 85; antigens; arabinogalactans; bacteria; Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; Biochemistry, Molecular Biology; biogenesis; Cell Membrane - enzymology; cell membranes; Corynebacterium; Corynebacterium - enzymology; Corynebacterium - genetics; Esterase; esterases; Fibronectin-binding protein; genes; Genomics; Life Sciences; lipids; metabolism; microbial physiology; Multigene Family; Mycobacterium; Mycolic Acids - metabolism; Mycolyltransferases; Mycomembrane; polymers; trehalose; vaccines; INH; Mycolyltransferases; DTT; HTS; TAT; Antigen 85; RND; (c,r)Myt(s); Fibronectin-binding protein; FITC; Esterase; Ag85; TDM; aa; Fbp(s); Mycomembrane; Mycobacterium; AG; ESI-MS; RMSD; DEP; mAGP; TMM; PG; Mar
• DOI: 10.1016/j.bbagen.2016.06.020
• ISSN: 0304-4165

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 •Mycoloyltransferases are key players in the biogenesis of Corynebacteriales envelope.•They transfer mycolates on sugars or proteins by a ping-pong mechanism.•The number of Myt paralogs in most Corynebacteriales varies between 3 and 9.•Myt are partially redundant but may also play specific roles in vivo.•Myt might be secreted through the inner membrane by different mechanisms.