Cross-chemistry leads to product diversity from atromentin synthetases in Aspergilli from section Nigri

Nonribosomal peptide synthetase (NRPS)-like enzymes catalyse the non-oxidative homodimerisation of aromatic α-keto acids, but the exact reaction mechanism is unknown. The furanone-forming thioesterase domain of the Aspergillus terreus aspulvinone E synthetase MelA displays a predicted quinone-forming motif, whereby its catalytic triad contains an essential cysteine indicating an unusual thioester intermediate. To convert MelA into a quinone-forming atromentin synthetase its thioesterase domain was replaced with that from a Paxillus involutus or A. terreus atromentin synthetase. Phylogenetic proximity of donor and acceptor seems important as only replacement with the A. terreus thioesterase was functional. Heterologous expression of atromentin synthetases in Aspergillus niger and Aspergillus oryzae revealed host-dependent product formation whereby cross-chemistry directed atromentin biosynthesis in A. niger towards atrofuranic acid. Screening of aspergilli from section Nigri identified an atromentin synthetase in Aspergillus brasiliensis that produced atrofuranic acid in the homologous host. Therefore, cross-chemistry on quinone cores appears common to section Nigri

Chemical chain termination resolves the timing of ketoreduction in a partially reducing iterative type I polyketide synthase

Synthetic chain terminators were used to capture the biosynthetic intermediates from a partially reducing iterative type I polyketide synthase, which is integrated into a multimodular biosynthesis enzyme. The off-loaded metabolites clarified the timing of ketoreduction and aromatization in the assembly of the antibiotic micacocidin

Micromonospora schwarzwaldensis sp. nov., a producer of telomycin, isolated from soil

A Gram-positive, spore-forming actinomycete strain (HKI0641T) was isolated from a soil sample collected in the Black Forest, Germany. During a screening for antimicrobial natural products this bacterium was identified as a producer of the antibiotic telomycin. Morphological characteristics and chemotaxonomic data suggested that the strain belongs to the genus Micromonospora. The peptidoglycan contains meso-diaminopimelic acid, and the fatty acid profile consists predominantly of anteiso-C15:0, iso-C15:0, iso-C16:0 and C16:0. MK-10(H4), MK-10(H2) and MK-10 were identified as the major menaquinones. To determine the taxonomic positioning of strain HKI0641T, we computed a binary tanglegram of two rooted phylogenetic trees that were based upon 16S rRNA and gyrB gene sequences, respectively. The comparative analysis of the two common classification methods strongly supported the phylogenetic affiliation with the genus Micromonospora, but it also revealed discrepancies in the assignment at the level of the genomic species. 16S rRNA gene sequence analysis identified M. coxensis DSM 45161T (99.1%) and M. marina DSM 45555T (99.0%) as the nearest taxonomic neighbours, whereas the gyrB sequence of strain HKI0641T indicated a closer relationship to M. aurantiaca DSM 43813T (95.1%). By means of DNA-DNA hybridization experiments, it was possible to resolve this issue and to clearly differentiate strain HKI0641T from other Micromonospora species. The type strains of the aforementioned Micromonospora species could be further distinguished from strain HKI0641T by several phenotypic properties, such as colony colour, NaCl tolerance and the utilization of carbon sources. The isolate was therefore assigned to a new species, for which the name Micromonospora schwarzwaldensis sp. nov. is proposed. The type strain is HKI0641T (= DSM 45708T = CIP 110415T).Fil: Vela Gurovic, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Hans-Knöll-Institute; AlemaniaFil: Müller, Sebastian. Hans-Knöll-Institute; AlemaniaFil: Domin, Nicole. Hans-Knöll-Institute; AlemaniaFil: Seccareccia, Ivana. Hans-Knöll-Institute; AlemaniaFil: Nietzsche, Sandor. University Hospital Jena; AlemaniaFil: Martin, Karin. Hans-Knöll-Institute; AlemaniaFil: Nett, Markus. Hans-Knöll-Institute; Alemani

Complete genome sequence of the filamentous gliding predatory bacterium Herpetosiphon aurantiacus type strain (114-95T)

Herpetosiphon aurantiacus Holt and Lewin 1968 is the type species of the genus Herpetosiphon, which in turn is the type genus of the family Herpetosiphonaceae, type family of the order Herpetosiphonales in the phylum Chloroflexi. H. aurantiacus cells are organized in filaments which can rapidly glide. The species is of interest not only because of its rather isolated position in the tree of life, but also because Herpetosiphon ssp. were identified as predators capable of facultative predation by a wolf pack strategy and of degrading the prey organisms by excreted hydrolytic enzymes. The genome of H. aurantiacus strain 114-95T is the first completely sequenced genome of a member of the family Herpetosiphonaceae. The 6,346,587 bp long chromosome and the two 339,639 bp and 99,204 bp long plasmids with a total of 5,577 protein-coding and 77 RNA genes was sequenced as part of the DOE Joint Genome Institute Program DOEM 2005

Socio-Informatics

Contents Editorial Thematic Focus: Socio-Informatics Introduction to the Thematic Focus “Socio-Informatics” / Claudia Müller Digitalisation in Small German Metal-Working Companies. Appropriation of Technology in a “Traditional” Industrial Domain / Bernhard Nett, Jennifer Bönsch Travelling by Taxi Brousse in Madagascar: An Investigation into Practices of Overland Transportation / Volker Wulf, Kaoru Misaki, Dave Randall, and Markus Rohde Mobile and Interactive Media in the Store? Design Case Study on Bluetooth Beacon Concepts for Food Retail / Christian Reuter, Inken Leopold Facebook and the Mass Media in Tunisia / Konstantin Aal, Marén Schorch, Esma Ben Hadj Elkilani, Volker Wulf Book Review Symposium Charles Goodwin Charles Goodwin’s Co-Operative Action: The Idea and the Argument / Erhard Schüttpelz, Christian Meyer Multi-Modal Interaction and Tool-Making: Goodwin’s Intuition / Christian Meyer, Erhard Schüttpelz Co-Operation is a Feature of Sociality, not an Attribute of People : “We inhabit each other’s actions.” (Goodwin, cover) / Jutta Wiesemann, Klaus Amann The Making of the World in Co-Operative Action. From Sentence Construction to Cultural Evolution / Jürgen Streeck On Goodwin and his Co-Operative Action / Jörg R. Bergman

Minimum Information about a Biosynthetic Gene cluster

A wide variety of enzymatic pathways that produce specialized metabolites in bacteria, fungi and plants are known to be encoded in biosynthetic gene clusters. Information about these clusters, pathways and metabolites is currently dispersed throughout the literature, making it difficult to exploit. To facilitate consistent and systematic deposition and retrieval of data on biosynthetic gene clusters, we propose the Minimum Information about a Biosynthetic Gene cluster (MIBiG) data standard.Chemistry and Chemical Biolog

Complete Genome Sequence of the Lignocellulose-Degrading Actinomycete Streptomyces albus CAS922

Streptomyces albus CAS922 was isolated from sunflower seed hulls. Its fully sequenced genome harbors a multitude of genes for carbohydrate-active enzymes, which likely facilitate growth on lignocellulosic biomass. Furthermore, the presence of 27 predicted biosynthetic gene clusters indicates a significant potential for the production of bioactive secondary metabolites.Fil: Tippelt, Anna. Universität Dortmund; AlemaniaFil: Nett, Markus. Universität Dortmund; AlemaniaFil: Vela Gurovic, Maria Soledad. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentin

Aurachins, Bacterial Antibiotics Interfering with Electron Transport Processes

Aurachins are farnesylated quinolone alkaloids of bacterial origin and excellent inhibitors of the respiratory chain in pro- and eukaryotes. Therefore, they have become important tool compounds for the investigation of electron transport processes and they also serve as lead structures for the development of antibacterial and antiprotozoal drugs. Especially aurachin D proved to be a valuable starting point for structure-activity relationship studies. Aurachin D is a selective inhibitor of the cytochrome bd oxidase, which has received increasing attention as a target for the treatment of infectious diseases caused by mycobacteria. Moreover, aurachin D possesses remarkable activities against Leishmania donovani, the causative agent of leishmaniasis. Aurachins are naturally produced by myxobacteria of the genus Stigmatella as well as by some Streptomyces and Rhodococcus strains. The recombinant production of these antibiotics turned out to be challenging due to their complex biosynthesis and their inherent toxicity. Recently, the biotechnological production of aurachin D was established in E. coli with a titer which is higher than previously reported from natural producer organisms