Paula Ravnikar

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There exists in Escherichia coli a known set of enzymes that were shown to function in an efficient and concerted way to convert threonine to serine. The sequence of reactions catalyzed by these enzymes is designated the Tut cycle (threonine utilization). To demonstrate that the relevant genes and their protein products play essential roles in serine(More)
In Synechocystis 6803 the psbA gene, encoding the Dl polypeptide of the Photosystem II reaction center, belongs to a multigene family with three copies (1). The nucleotide sequence of psbA-1 has been reported (2). We have cloned and seguenced a seconcl psbA gene, psbA-2. front Svnechocvstis 6803. The second copy of psbA i s contained within a 2.1 Kb genomic(More)
The threonine dehydrogenase (tdh) gene of Escherichia coli, cloned within the plasmid pDR121, was inactivated in vitro by inserting a segment of DNA carrying the chloramphenicol acetyltransferase (cat) gene. The insertionally inactivated tdh gene was then transferred by homologous recombination into the E. coli chromosome by the procedure of Winans et al.(More)
The plasmid pDR121 is a pBR322 derivative that contains a 3.7-kilobase-pair EcoRI fragment of DNA from the 81.2-min region of the Escherichia coli chromosome. The genomic insert encodes threonine dehydrogenase and at least one other protein. Several physical and kinetic properties of threonine dehydrogenase, overproduced in cells harboring pDR121, are(More)
The productivity of stably transfected cell lines is of critical importance for the manufacturing of therapeutic proteins. Various methods have been successfully implemented to increase the production output of mammalian cell cultures. Increasing evidence suggests that optimization of the gene coding sequences of an expression vector can improve specific(More)
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