Publications by authors named "Jennifer Ambrad"

Down-regulation of expression of trmD, encoding the enzyme tRNA (guanosine-1)-methyltransferase, has shown that this gene is essential for growth of Streptococcus pneumoniae. The S. pneumoniae trmD gene has been isolated and expressed in Escherichia coli by using a His-tagged T7 expression vector.

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Attempted allelic replacement of 144 Streptococcus pneumoniae open reading frames of previously uncharacterized function led to the identification of 36 genes essential for growth under laboratory conditions. Of these, 14 genes (obg, spoIIIJ2, trmU, yacA, yacM, ydiC, ydiE, yjbN, yneS, yphC, ysxC, ytaG, yloI and yxeH4) were also essential in Staphylococcus aureus and Haemophilus influenzae or Escherichia coli, 2 genes (yrrK and ydiB) were only essential in H. influenzae as well as S.

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The promoter of the Streptococcus pneumoniae putative fuculose kinase gene (fcsK), the first gene of a novel fucose utilization operon, is induced by fucose and repressed by glucose or sucrose. When the streptococcal polypeptide deformylase (PDF) gene (def1, encoding PDF) was placed under the control of P(fcsK), fucose-dependent growth of the S. pneumoniae (P(fcsK)::def1) strain was observed, confirming the essential nature of PDF in this organism.

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