Operons

Operons (clusters of co-regulated genes with related functions) are common features of bacterial genomes. More recently, functional gene clustering has been reported in eukaryotes, from yeasts to filamentous fungi, plants, and animals. Gene clusters can consist of paralogous genes that have most likely arisen by gene duplication. However, there are now many examples of eukaryotic gene clusters that contain functionally related but non-homologous genes and that represent functional gene organizations with operon-like features (physical clustering and co-regulation). These include gene clusters for use of different carbon and nitrogen sources in yeasts, for production of antibiotics, toxins, and virulence determinants in filamentous fungi, for production of defense compounds in plants, and for innate and adaptive immunity in animals (the major histocompatibility locus). The aim of this article is to review features of functional gene clusters in prokaryotes and eukaryotes and the significance of clustering for effective function

A one-pot enzymatic approach to the O-fluoroglucoside of N-methylanthranilate.

In connection with prospective (18)F-PET imaging studies, the potential for enzymatic synthesis of fluorine-labelled glycosides of small molecules was investigated. Approaches to the enzymatic synthesis of anomeric phosphates of d-gluco-configured fluorosugars proved ineffective. In contrast, starting in the d-galacto series and relying on the consecutive action of Escherichia coli galactokinase (GalK), galactose-1-phosphate uridylyltransferase (GalPUT), uridine-5′-diphosphogalactose 4-epimerase (GalE) and oat root glucosyltransferase (SAD10), a quick and effective synthesis of 6-deoxy-6-fluoro-d-glucosyl N-methylanthranilate ester was achieved

A one-pot enzymatic approach to the O-fluoroglucoside of N-methylanthranilate

In connection with prospective 18F-PET imaging studies, the potential for enzymatic synthesis of fluorine-labelled glycosides of small molecules was investigated. Approaches to the enzymatic synthesis of anomeric phosphates of d-gluco-configured fluorosugars proved ineffective. In contrast, starting in the d-galacto series and relying on the consecutive action of Escherichia coli galactokinase (GalK), galactose-1-phosphate uridylyltransferase (GalPUT), uridine-5′-diphosphogalactose 4-epimerase (GalE) and oat root glucosyltransferase (SAD10), a quick and effective synthesis of 6-deoxy-6-fluoro-d-glucosyl N-methylanthranilate ester was achieved

Expression of the Escherichia coli β-glucuronidase gene in industrial and phytopathogenic filamentous fungi

A chimaeric β-glucuronidase (GUS) gene has been created by ligating the Aspergillus nidulans glyceraldehyde 3-phosphate dehydrogenase promoter to the coding sequence of the E. coli uidA gene. Cotransformation of this vector into A. nidulans, A. niger and the tomato pathogen Fulvia fulva (syn. Cladosporium fulvum (Cooke)) resulted in the expression of β-glucuronidase. GUS activity was detected by growth on agar media containing X-gluc and by enzyme assays of mycelial extracts. Expression of the gene in F. fulva transformants was also easily detectable during growth in plants and did not affect pathogenicity. These results form the basis for a versatile and sensitive reporter gene system for industrial and phytopathogenic filamentous fungi