Fastidian gum: the Xylella fastidiosa exopolysaccharide possibly involved in bacterial pathogenicity.
The Gram-negative bacterium Xylella fastidiosa was the first plant pathogen to be completely sequenced. This species causes several economically important plant diseases, including citrus variegated chlorosis (CVC). Analysis of the genomic sequence of X. fastidiosa revealed a 12 kb DNA fragment containing an operon closely related to the gum operon of Xanthomonas campestris. The presence of all genes involved in the synthesis of sugar precursors, existence of exopolysaccharide (EPS) production regulators in the genome, and the absence of three of the X. campestris gum genes suggested that X. fastidiosa is able to synthesize an EPS different from that of xanthan gum. This novel EPS probably consists of polymerized tetrasaccharide repeating units assembled by the sequential addition of glucose-1-phosphate, glucose, mannose and glucuronic acid on a polyprenol phosphate carrier.
da Silva
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Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), Caixa Postal 6010, CEP 13083-970, Campinas, São Paulo, Brazil.
Vettore
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Kemper
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Leite
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Arruda
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D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D018441:Biofilms; D002240:Carbohydrate Sequence; D002957:Citrus / Q000382:microbiology*; D020563:Gammaproteobacteria / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D009876:Operon; D010935:Plant Diseases / Q000382:microbiology; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D014774:Virulence
D001426:Bacterial Proteins; D011135:Polysaccharides, Bacterial