5 research outputs found
Disruption of Mycobacterial AftB Results in Complete Loss of Terminal β(1 → 2) Arabinofuranose Residues of Lipoarabinomannan
Lipoarabinomannan
(LAM) and arabinogalactan (AG) are the two major
mycobacterial cell wall (lipo)polysaccharides, which contain a structurally
similar arabinan domain that is highly branched and assembled in a
stepwise fashion by variety of arabinofuranosyltransferases (Ara<i>f</i>T). In addition to playing an essential role in mycobacterial
physiology, LAM and its biochemical precursor lipomannan possess potent
immunomodulatory activities that affect the host immune response.
In the search of additional mycobacterial Ara<i>f</i>Ts
that participate in the synthesis of the arabinan segment of LAM,
we disrupted <i>aftB</i> (<i>MSMEG_6400</i>) in <i>Mycobacterium smegmatis</i>. The deletion of chromosomal <i>aftB</i> locus could only be achieved in the presence of a rescue
plasmid carrying a functional copy of <i>aftB</i>, strongly
suggesting that it is essential for the viability of <i>M. smegmatis</i>. Isolation and detailed structural characterization of a LAM molecule
derived from the conditional mutant deficient in AftB revealed the
absence of terminal β(1 → 2)-linked arabinofuranosyl
residues. Furthermore, we demonstrated that truncated LAM displays
proinflammatory activity, which is due to its ability to activate
Toll-like receptor 2. All together, our results indicate that AftB
is an essential mycobacterial Ara<i>f</i>T that plays a
role in the synthesis of the arabinan domain of LAM
MOESM1 of Combinatorial optimization of synthetic operons for the microbial production of p-coumaryl alcohol with Escherichia coli
Additional file 1. Supplementary Information
Additional file 1 of Robotic workflows for automated long-term adaptive laboratory evolution: improving ethanol utilization by Corynebacterium glutamicum
Supplementary Material
Additional file 1 of Itaconate Production from Crude Substrates with U. maydis: Scale-up of an Industrially Relevant Bioprocess
Supplementary Material
<i>Corynebacterium glutamicum</i> Chassis C1*: Building and Testing a Novel Platform Host for Synthetic Biology and Industrial Biotechnology
Targeted
top-down strategies for genome reduction are considered
to have a high potential for providing robust basic strains for synthetic
biology and industrial biotechnology. Recently, we created a library
of 26 genome-reduced strains of <i>Corynebacterium glutamicum</i> carrying broad deletions in single gene clusters and showing wild-type-like
biological fitness. Here, we proceeded with combinatorial deletions
of these irrelevant gene clusters in two parallel orders, and the
resulting library of 28 strains was characterized under various environmental
conditions. The final chassis strain C1* carries a genome reduction
of 13.4% (412 deleted genes) and shows wild-type-like growth behavior
in defined medium with d-glucose as carbon and energy source.
Moreover, C1* proves to be robust against several stresses (including
oxygen limitation) and shows long-term growth stability under defined
and complex medium conditions. In addition to providing a novel prokaryotic
chassis strain, our results comprise a large strain library and a
revised genome annotation list, which will be valuable sources for
future systemic studies of <i>C. glutamicum</i>