J F Martin

..The major degradation product was xylobiose with traces of xylose. The xylanase activity was thermostable, showing a good activity up to 95 degrees C, and had broad pH stability in the range from pH 4.0 to pH 10.0...

..These results indicate that expression of the gdhA gene is subject to a strong nitrogen regulation at the transcriptional level...

..The availability of this gene provides a very useful tool for understanding the proposed role of cystathionine-gamma-lyase in splitting cystathionine to supply cysteine for cephalosporin biosynthesis...

..The PhoP regulation of several of these genes has been studied in detail using EMSA and DNase I footprinting studies as well as in vivo expression studies with reporter genes and RT-PCR transcriptomic analyses...

..Using protein extracts from mycelia grown under carbon catabolite repressing or derepressing conditions DNA-binding proteins that interact with the bidirectional promoter region were purified to near homogeneity...

..Genetic improvement of the secretion systems of secondary metabolites in the producer strain has important industrial applications...

..Eliminating cystathionine-gamma-lyase prevents the enhancing precursor effect of methionine on cephalosporin-C production, and cystathionine-gamma-lyase overproduction in moderate doses increases cephalosporin-C formation...

..Some specific ribosomal protein genes are located in a different cluster in C. glutamicum when compared with E. coli, indicating that the control of expression of these genes is different in E. coli and C. glutamicum...

..Several new beta-lactam antibiotics have been discovered in gram-positive and gram-negative bacteria that will provide new genes for combinatorial synthesis of new molecules...

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..These results indicate that the folate branch is essential for methionine biosynthesis in streptomycetes, as occurs in enterobacteria...

..The levels of the cefG transcript were very low as compared to those of pcbAB, pcbC and cefEF.(ABSTRACT TRUNCATED AT 400 WORDS)..

..The '114-bp' fragment is A + T-rich (54%), as compared to the Streptomyces genome (70-73% GC). The presence of a phosphate control sequence (pcs) in the upstream region of the pabS gene is proposed...

..The difference in localization of homocitrate synthase between P. chrysogenum and S. cerevisiae suggests that this protein may play a regulatory function, in addition to its catalytic function, in S. cerevisiae but not in P. chrysogenum...

..Levels of methionine induction of the cephalosporin biosynthesis gene pcbC were identical in the parental strain and the mecB mutants, indicating that the induction effect is not mediated by cystathionine-gamma-lyase...

..The hrdT gene is weakly transcribed (1.5-kb RNA) under all conditions tested. The hrd-encoded sigma factors probably recognize actinomycetes promoters (SEP type) with E. coli-like consensus sequences...

..The protein encoded by this open reading frame had little similarity to any protein in the data banks, and its function remains unknown. The three genes were translated in Escherichia coli, giving the corresponding polypeptides...

..The transcription of these genes is repressed by lysine and induced by arginine, showing an interesting pattern of biosynthetic interlock between the pathways of both amino acids in corynebacteria...

..The thrB promoter was located in an 87-bp fragment that overlaps with the end of the hom gene. A functional transcriptional terminator located downstream from the cluster was subcloned in terminator-probe vectors...

..lactamdurans' is regulated by the concerted action of lysine plus threonine and this inhibition is abolished in E. coli transformants containing Ser(301) to Tyr, or Gly(345) to Asp mutations of the 'A. lactamdurans' ask gene...

..The pab gene hybridizes with 6 out of 16 Streptomyces strains, and those strains which hybridize turned out to be polyene producers. Such strains were never before described as polyene producers...

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..Amplification of argG in transformant Scl[pULAR113] results in a 2.3-fold increase in the production of clavulanic acid (CA) in relation to the control strain Scl[pIJ699]...

..sigB is closely linked to the dtxR gene (encoding a repressor of iron-regulated promoters homologous to the diphtheria toxin repressor from Corynebacterium diphtheriae...

..Amino acid comparison of nine threonine synthases revealed evolutionary relationships between different groups of bacteria...

..Removal of bottlenecks has been achieved by amplification of genes which encode feedback resistant aspartokinase and homoserine dehydrogenase (obtained by in vitro directed mutagenesis)...

..In conclusion, moderately increased levels of cystathionine-gamma-lyase stimulated cephalosporin production but very high levels of this enzyme were deleterious for growth and cephalosporin biosynthesis...

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..The penDE gene of A. nidulans is linked to the pcbC gene, which encodes the isopenicillin N synthase, as also occurs in P. chrysogenum. Both genes show the same orientation and are separated by an intergenic region of 822 nucleotides...

..Pi-deregulated mutants, described previously, were impaired in the transcriptional control exerted by Pi. It is concluded that Pi control of PABA synthase and Cd biosynthesis is exerted by repression of formation of the pabS mRNA...

..Genetic stabilization of a monocopy system was obtained when both pyrG repeats (formed at the targeted integration site) contained at least one identical mutation, since in this case further recombinations can be easily counter-selected...

..In addition, the dmdR gene was also expressed as a monocistronic 0.7-kb transcript during the active growth phase...

..It seems that the CefT protein is involved in cephalosporin export from A. chrysogenum or in transmembrane signal transduction, and that there are redundant systems involved in cephalosporin export...

..B. lactofermentum R31 mutants do not overproduce lysine because R31 is an alanine-overproducing strain and channels the pyruvate needed for lysine biosynthesis to the production of alanine...

..Comparison of proteins reveals much larger differences for primary metabolism enzymes than for beta-lactam biosynthesis enzymes in producing organisms. This suggests a horizontal transfer of the beta-lactam antibiotic biosynthesis genes...

..From computer analysis of sequence data, PC sequences appear to be associated with promoter regions of several phosphate-controlled antibiotic biosynthetic genes...

..8-kDa protein, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme required pyridoxal phosphate as its only cofactor to convert homoserine phosphate into threonine...

..These results prove that expression of both phoA and genes implicated in the biosynthesis of secondary metabolites in S. lividans is regulated by a mechanism involving the two-component PhoR-PhoP system...

..Protein P8 may act as a coupling protein for efficient hydroxylation at C-7 in a form similar to that of the two-component system of Pseudomonas putida p-hydroxyphenylacetate-3-hydroxylase...

..Formation of PABA synthase and candicidin production was equally sensitive to phosphate regulation in transformants with the pabAB than in the untransformed S. acrimycini strain...

..This is the first example of a clear regulation of an amino acid biosynthetic pathway in Streptomyces species, challenging the belief that actinomycetes do not have a well-developed regulatory system of these pathways...

..The promoters of the nusG and rplK-rplA genes were subcloned in a novel corynebacterial promoter-probe vector and shown to confer strong expression of the reporter gene...

..These results indicate that L-lysine is required not only for antibiotic biosynthesis, but particularly as carbon or nitrogen source...

..The deletion occurred when the gene was cloned in the BamHI site of pBR322 and allowed pab expression in E. coli...

..Footprinting experiments indicated that triple heptameric conserved sequences were protected by r-CcaR, and allowed identification of heptameric sequences as CcaR binding sites...

..The alpha-aminoadipic acid precursor is channelled to penicillin biosynthesis by blocking the lysine biosynthesis branch at the alpha-aminoadipate reductase level...

..We set out to clone, sequence and analyse the gene cluster responsible for the biosynthesis of this tetraene...

..In summary, we describe for the first time a modulator of beta-lactam intermediate transporters in A. chrysogenum...

..The extents of induction by increasing concentrations of the chelator 2,2'-dipyridyl were identical in cells expressing DtxR from either C. diphtheriae or B. lactofermentum...

..This information was used to clone the gene encoding this enzyme...

..Antibiotic and pigment production, and low transformability with plasmid DNA were together restored in spontaneous spo+ revertants...

..The enzymes which catalyze these last three steps are encoded by the genes cefE, cefF and cefG. The penicillin, cephalosporin and cephamycin biosynthetic genes are organized in clusters (and subclusters) of genes...

..Transformation of S. clavuligerus 328, an argC auxotroph deficient in clavulanic acid biosynthesis, with plasmid pULML30, carrying the cloned argC gene, restored both prototrophy and antibiotic production...

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..coelicolor M1154 strain, suggesting that heterologous expression in S. coelicolor might be toxic due to the lack of an holomycin resistance gene in this host strain...

..Andrastin A was present in all industrial and local varieties of blue cheese. The content of andrastin A was similar to that of other well-known blue cheeses from France and Denmark...

..Among all proteins, three showed significant associations between protein recognition and the titre of IgA in the serum...