@article {686,
	title = {Identification of a second catalytically active trans-sialidase in Trypanosoma brucei.},
	journal = {Biochem Biophys Res Commun},
	volume = {415},
	year = {2011},
	month = {2011 Nov 18},
	pages = {421-5},
	abstract = {The procyclic stage of Trypanosoma brucei is covered by glycosylphosphatidylinositol (GPI)-anchored surface proteins called procyclins. The procyclin GPI anchor contains a side chain of N-acetyllactosamine repeats terminated by sialic acids. Sialic acid modification is mediated by trans-sialidases expressed on the parasite{\textquoteright}s cell surface. Previous studies suggested the presence of more than one active trans-sialidases, but only one has so far been reported. Here we cloned and examined enzyme activities of four additional trans-sialidase homologs, and show that one of them, Tb927.8.7350, encodes another active trans-sialidase, designated as TbSA C2. In an in vitro assay, TbSA C2 utilized α2-3 sialyllactose as a donor, and produced an α2-3-sialylated product, suggesting that it is an α2-3 trans-sialidase. We suggest that TbSA C2 plays a role in the sialic acid modification of the trypanosome cell surface.},
	keywords = {Amino Sugars, Catalysis, Cell Membrane, Cloning, Molecular, Glycoproteins, Glycosylphosphatidylinositols, Mutation, N-Acetylneuraminic Acid, Neuraminidase, Trypanosoma brucei brucei},
	issn = {1090-2104},
	doi = {10.1016/j.bbrc.2011.10.085},
	author = {Nakatani, Fumiki and Morita, Yasu S and Ashida, Hisashi and Nagamune, Kisaburo and Maeda, Yusuke and Kinoshita, Taroh}
}
@article {694,
	title = {Identification of a novel protein with a role in lipoarabinomannan biosynthesis in mycobacteria.},
	journal = {J Biol Chem},
	volume = {281},
	year = {2006},
	month = {2006 Apr 7},
	pages = {9011-7},
	abstract = {All species of Mycobacteria synthesize distinctive cell walls that are rich in phosphatidylinositol mannosides (PIMs), lipomannan (LM), and lipoarabinomannan (LAM). PIM glycolipids, having 2-4 mannose residues, can either be channeled into polar PIM species (with 6 Man residues) or hypermannosylated to form LM and LAM. In this study, we have identified a Mycobacterium smegmatis gene, termed lpqW, that is required for the conversion of PIMs to LAM and is highly conserved in all mycobacteria. A transposon mutant, Myco481, containing an insertion near the 3{\textquoteright} end of lpqW exhibited altered colony morphology on complex agar medium. This mutant was unstable and was consistently overgrown by a second mutant, represented by Myco481.1, that had normal growth and colony characteristics. Biochemical analysis and metabolic labeling studies showed that Myco481 synthesized the complete spectrum of apolar and polar PIMs but was unable to make LAM. LAM biosynthesis was restored to near wild type levels in Myco481.1. However, this mutant was unable to synthesize the major polar PIM (AcPIM6) and accumulated a smaller intermediate, AcPIM4. Targeted disruption of the lpqW gene and complementation of the initial Myco481 mutant with the wild type gene confirmed that the phenotype of this mutant was due to loss of LpqW. These studies suggest that LpqW has a role in regulating the flux of early PIM intermediates into polar PIM or LAM biosynthesis. They also suggest that AcPIM4 is the likely branch point intermediate in polar PIM and LAM biosynthesis.},
	keywords = {Cell Membrane, Gene Expression Regulation, Bacterial, Genes, Bacterial, Lipopolysaccharides, Mutation, Mycobacterium smegmatis, Phenotype, Phosphatidylinositols, Virulence},
	issn = {0021-9258},
	doi = {10.1074/jbc.M511709200},
	author = {Kovacevic, Svetozar and Anderson, Dianne and Morita, Yasu S and Patterson, John and Haites, Ruth and McMillan, Benjamin N I and Coppel, Ross and McConville, Malcolm J and Billman-Jacobe, Helen}
}
@article {696,
	title = {Compartmentalization of lipid biosynthesis in mycobacteria.},
	journal = {J Biol Chem},
	volume = {280},
	year = {2005},
	month = {2005 Jun 3},
	pages = {21645-52},
	abstract = {The plasma membrane of Mycobacterium sp. is the site of synthesis of several distinct classes of lipids that are either retained in the membrane or exported to the overlying cell envelope. Here, we provide evidence that enzymes involved in the biosynthesis of two major lipid classes, the phosphatidylinositol mannosides (PIMs) and aminophospholipids, are compartmentalized within the plasma membrane. Enzymes involved in the synthesis of early PIM intermediates were localized to a membrane subdomain termed PMf, that was clearly resolved from the cell wall by isopyknic density centrifugation and amplified in rapidly dividing Mycobacterium smegmatis. In contrast, the major pool of apolar PIMs and enzymes involved in polar PIM biosynthesis were localized to a denser fraction that contained both plasma membrane and cell wall markers (PM-CW). Based on the resistance of the PIMs to solvent extraction in live but not lysed cells, we propose that polar PIM biosynthesis occurs in the plasma membrane rather than the cell wall component of the PM-CW. Enzymes involved in phosphatidylethanolamine biosynthesis also displayed a highly polarized distribution between the PMf and PM-CW fractions. The PMf was greatly reduced in non-dividing cells, concomitant with a reduction in the synthesis and steady-state levels of PIMs and amino-phospholipids and the redistribution of PMf marker enzymes to non-PM-CW fractions. The formation of the PMf and recruitment of enzymes to this domain may thus play a role in regulating growth-specific changes in the biosynthesis of membrane and cell wall lipids.},
	keywords = {Bacterial Proteins, Biochemistry, Cell Membrane, Cell Wall, Hemagglutinins, Lipid Metabolism, Lipids, Mannosides, Mannosyltransferases, Microscopy, Electron, Models, Biological, Mycobacterium smegmatis, Phosphatidylethanolamines, Phosphatidylinositols, Phospholipids, Protein Structure, Tertiary, Subcellular Fractions},
	issn = {0021-9258},
	doi = {10.1074/jbc.M414181200},
	author = {Morita, Yasu S and Velasquez, Ren{\'e} and Taig, Ellen and Waller, Ross F and Patterson, John H and Tull, Dedreia and Williams, Spencer J and Billman-Jacobe, Helen and McConville, Malcolm J}
}
