POSTERS - BLAST X - University of Utah
POSTERS - BLAST X - University of Utah
POSTERS - BLAST X - University of Utah
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<strong>BLAST</strong> X ______ Poster #8<br />
NUTRIENT SENSING BY A HUMAN GUT SYMBIONT<br />
Hongjun Zheng 1 , Susan Firbank 1 , Eric Martens 2 , Edith Diaz 1 , Rick Lewis 1 , Jeff Gordon 2 and<br />
David Bolam 1<br />
1. Institute for Cell and Molecular Biosciences, Newcastle <strong>University</strong>, The Medical School,<br />
Framlington Place, Newcastle upon Tyne NE2 4HH, UK<br />
2. Center for Genome Sciences, Washington <strong>University</strong>, St Louis, USA.<br />
The gut microbiota play an important role in human health and nutrition. Bacteroides<br />
thetaiotaomicron (Bt) is a dominant gut symbiont whose main sources <strong>of</strong> carbon and energy are<br />
dietary and host polysaccharides, reflected in the presence on the genome <strong>of</strong> a large number <strong>of</strong><br />
genes involved in the sensing, acquisition and processing <strong>of</strong> complex carbohydrates. One <strong>of</strong> the<br />
most striking features <strong>of</strong> the Bt genome are 33 genes encoding novel hybrid two component<br />
systems (HTCS) that contain all <strong>of</strong> the domains <strong>of</strong> a classical TCS in a single polypeptide.<br />
Custom Genechip arrays reveal that when Bt is grown in the presence <strong>of</strong> inulin, a β-1,2 linked<br />
fructose storage polysaccharide, a specific locus composed <strong>of</strong> eight genes predicted to be<br />
involved in polysaccharide binding, uptake and degradation is activated. The closest regulatory<br />
protein to this locus is an HTCS, BT1754. Genetic, biochemical and structural studies reveal<br />
that BT1754 is the sensor that controls fructan utilisation and the identity <strong>of</strong> the signalling<br />
molecule itself, as well as the mechanism <strong>of</strong> signal perception and insights into signal<br />
transduction across the cytoplasmic membrane.<br />
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