MKAN27435 is required for the biosynthesis of higher subclasses of lipooligosaccharides in Mycobacterium kansasii.

Vijayashankar Nataraj, Poh-choo Pang, Stuart M Haslam, Natacha Veerapen, David E Minnikin, Anne Dell, Gurdyal S Besra, Apoorva Bhatt

Index: PLoS ONE 10(3) , e0122804, (2015)

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Abstract

Lipooligosaccharides are glycolipids found in the cell wall of many mycobacterial species including the opportunistic pathogen Mycobacterium kansasii. The genome of M. kansasii ATCC12478 contains a cluster with genes orthologous to Mycobacterium marinum LOS biosynthesis genes. To initiate a genetic dissection of this cluster and demonstrate its role in LOS biosynthesis in M. kansasii, we chose MKAN27435, a gene encoding a putative glycosyltransferase. Using Specialized Transduction, a phage-based gene knockout tool previously used to generate null mutants in other mycobacteria, we generated a MKAN27435 null mutant. The mutant strain was found to be defective in the biosynthesis of higher LOS subspecies, viz LOS-IV, LOS-V, LOS-VI and LOS-VII. Additionally, a range of low abundance species were detected in the mutant strain and mass spectroscopic analysis indicated that these were shunt products generated from LOS-III by the addition of up to six molecules of a pentose.