@article {2620,
	title = {Engineering the Mycomembrane of Live Mycobacteria with an Expanded Set of Trehalose Monomycolate Analogues.},
	journal = {Chembiochem},
	volume = {20},
	year = {2019},
	month = {2019 05 15},
	pages = {1282-1291},
	abstract = {<p>Mycobacteria and related organisms in the Corynebacterineae suborder are characterized by a distinctive outer membrane referred to as the mycomembrane. Biosynthesis of the mycomembrane occurs through an essential process called mycoloylation, which involves antigen 85 (Ag85)-catalyzed transfer of mycolic acids from the mycoloyl donor trehalose monomycolate (TMM) to acceptor carbohydrates and, in some organisms, proteins. We recently described an alkyne-modified TMM analogue (O-AlkTMM-C7) which, in conjunction with click chemistry, acted as a chemical reporter for mycoloylation in intact cells and allowed metabolic labeling of mycoloylated components of the mycomembrane. Here, we describe the synthesis and evaluation of a toolbox of TMM-based reporters bearing alkyne, azide, trans-cyclooctene, and fluorescent tags. These compounds gave further insight into the substrate tolerance of mycoloyltransferases (e.g., Ag85s) in a cellular context and they provide significantly expanded experimental versatility by allowing one- or two-step cell labeling, live cell labeling, and rapid cell labeling via tetrazine ligation. Such capabilities will facilitate research on mycomembrane composition, biosynthesis, and dynamics. Moreover, because TMM is exclusively metabolized by Corynebacterineae, the described probes may be valuable for the specific detection and cell-surface engineering of Mycobacterium tuberculosis and related pathogens. We also performed experiments to establish the dependence of probe incorporation on mycoloyltransferase activity, results from which suggested that cellular labeling is a function not only of metabolic incorporation (and likely removal) pathway(s), but also accessibility across the envelope. Thus, whole-cell labeling experiments with TMM reporters should be carefully designed and interpreted when envelope permeability may be compromised. On the other hand, this property of TMM reporters can potentially be exploited as a convenient way to probe changes in envelope integrity and permeability, facilitating drug development studies.</p>
},
	keywords = {Acyltransferases, Alkynes, Azides, Bacillus subtilis, Cell Engineering, Cell Membrane, Click Chemistry, Cord Factors, Corynebacterium, Escherichia coli, Fluorescent Dyes, Molecular Structure, Mycobacterium smegmatis, Mycobacterium tuberculosis},
	issn = {1439-7633},
	doi = {10.1002/cbic.201800687},
	author = {Fiolek, Taylor J and Banahene, Nicholas and Kavunja, Herbert W and Holmes, Nathan J and Rylski, Adrian K and Pohane, Amol Arunrao and Siegrist, M Sloan and Swarts, Benjamin M}
}
@article {1440,
	title = {Subpolar addition of new cell wall is directed by DivIVA in mycobacteria.},
	journal = {Proc Natl Acad Sci U S A},
	volume = {111},
	year = {2014},
	month = {2014 Aug 5},
	pages = {E3243-51},
	abstract = {<p>Mycobacteria are surrounded by a complex multilayered envelope and elongate at the poles. The principles that organize the coordinated addition of chemically diverse cell wall layers during polar extension remain unclear. We show that enzymes mediating the terminal cytosolic steps of peptidoglycan, arabinogalactan, and mycolic acid synthesis colocalize at sites of cell growth or division. The tropomyosin-like protein, DivIVA, is targeted to the negative curvature of the pole, is enriched at the growing end, and determines cell shape from this site. In contrast, cell wall synthetic complexes are concentrated at a distinct subpolar location. When viewed at subdiffraction resolution, new peptidoglycan is deposited at this subpolar site, and inert cell wall covers the DivIVA-marked tip. The differentiation between polar tip and cell wall synthetic complexes is also apparent at the biochemical level. Enzymes that generate mycolate precursors interact with DivIVA, but the final condensation of mycolic acids occurs in a distinct protein complex at the site of nascent cell wall addition. We propose an ultrastructural model of mycobacterial polar growth where new cell wall is added in an annular zone below the cell tip. This model may be broadly applicable to other bacterial and fungal organisms that grow via polar extension.</p>},
	keywords = {Bacterial Proteins, Cell Cycle Proteins, Cell Membrane, Cell Polarity, Cell Wall, Models, Biological, Mycobacterium smegmatis, Mycolic Acids, Protein Binding},
	issn = {1091-6490},
	doi = {10.1073/pnas.1402158111},
	author = {Meniche, Xavier and Otten, Renee and Siegrist, M Sloan and Baer, Christina E and Murphy, Kenan C and Bertozzi, Carolyn R and Sassetti, Christopher M}
}
