DNA affinity capturing identifies new regulators of the heterologously expressed novobiocin gene cluster in Streptomyces coelicolor M512.
Applied Microbiology and Biotechnology 100(10):4495 (2016)
Understanding the regulation of a heterologously expressed gene cluster in a host organism is crucial for activation of silent gene clusters or overproduction of the corresponding natural product. In this study, Streptomyces coelicolor M512(nov-BG1) containing the novobiocin biosynthetic gene cl...
Microbiology 162(5):727 (2016)
Enabling cell-cell communication via nanopore formation: structure, function and localization of the unique cell wall amidase AmiC2 of Nostoc punctiforme.
FEBS Journal 283(7):1336 (2016)
To orchestrate a complex life style in changing environments, the filamentous cyanobacterium Nostoc punctiforme facilitates communication between neighboring cells through septal junction complexes. This is achieved by nanopores that perforate the peptidoglycan (PGN) layer and traverse the cell ...
The Molecular Basis of TnrA Control by Glutamine Synthetase in Bacillus subtilis.
Journal of Biological Chemistry 291(7):3483 (2016)
TnrA is a master regulator of nitrogen assimilation in Bacillus subtilis. This study focuses on the mechanism of how glutamine synthetase (GS) inhibits TnrA function in response to key metabolites ATP, AMP, glutamine, and glutamate. We suggest a model of two mutually exclusive GS conformations g...
Septal Junctions in Filamentous Heterocyst-Forming Cyanobacteria.
Trends in Microbiology 24(2):79 (2016)
In the filaments of heterocyst-forming cyanobacteria, septal junctions that traverse the septal peptidoglycan join adjacent cells, allowing intercellular communication. Perforations in the septal peptidoglycan have been observed, and proteins involved in the formation of such perforations and pu...
Clear differences in metabolic and morphological adaptations of akinetes of two Nostocales living in different habitats.
Microbiology 162(2):214 (2016)
Akinetes are resting spore-like cells formed by some heterocyst-forming filamentous cyanobacteria for surviving long periods of unfavourable conditions. We studied the development of akinetes in two model strains of cyanobacterial cell differentiation, the planktonic freshwater Anabaena variabil...
Sensory properties of the PII signalling protein family.
FEBS Journal 283(3):425 (2016)
PII signalling proteins constitute one of the largest families of signalling proteins in nature. An even larger superfamily of trimeric sensory proteins with the same architectural principle as PII proteins appears in protein structure databases. Large surface-exposed flexible loops protrude fro...
Characterization of DNA Binding Sites of RokB, a ROK-Family Regulator from Streptomyces coelicolor Reveals the RokB Regulon.
PLoS ONE 11(5):e0153249 (2016)
ROK-family proteins have been described to act either as sugar kinases or as transcriptional regulators. Few ROK-family regulators have been characterized so far and most of them are involved in carbon catabolite repression. RokB (Sco6115) has originally been identified in a DNA-affinity capturi...
Polyhydroxyalkanoate (PHA) Granules Have no Phospholipids.
Scientific reports 6:26612 (2016)
Polyhydroxybutyrate (PHB) granules, also designated as carbonosomes, are supra-molecular complexes in prokaryotes consisting of a PHB polymer core and a surface layer of structural and functional proteins. The presence of suspected phospholipids in the surface layer is based on in vitro data of ...
Glutamine Assimilation and Feedback Regulation of L-acetyl-N-glutamate Kinase Activity in Chlorella variabilis NC64A Results in Changes in Arginine Pools.
Protist 166(5):493 (2015)
Glutamine is a metabolite of central importance in nitrogen metabolism of microorganisms and plants. The Chlorella PII signaling protein controls, in a glutamine-dependent manner, the key enzyme of the ornithine/arginine biosynthesis pathway, N-acetyl-L-glutamate kinase (NAGK) that leads to argi...
Reduction of PII signaling protein enhances lipid body production in Chlamydomonas reinhardtii.
Plant Science 240:1 (2015)
In all examined organisms that have the PII signal transduction machinery, PII coordinates the central C/N anabolic metabolism. In green algae and land plants, PII is localized in the chloroplast and controls the L-arginine biosynthetic pathway pathway. To elucidate additional functions of PII i...
Photoautotrophic Polyhydroxybutyrate Granule Formation Is Regulated by Cyanobacterial Phasin PhaP in Synechocystis sp. Strain PCC 6803.
Applied and Environmental Microbiology 81(13):4411 (2015)
Cyanobacteria are photoautotrophic microorganisms which fix atmospheric carbon dioxide via the Calvin-Benson cycle to produce carbon backbones for primary metabolism. Fixed carbon can also be stored as intracellular glycogen, and in some cyanobacterial species like Synechocystis sp. strain PCC 6...
The bacterial signal transduction protein GlnB regulates the committed step in fatty acid biosynthesis by acting as a dissociable regulatory subunit of acetyl-CoA carboxylase.
Molecular Microbiology 95(6):1025 (2015)
Biosynthesis of fatty acids is one of the most fundamental biochemical pathways in nature. In bacteria and plant chloroplasts, the committed and rate-limiting step in fatty acid biosynthesis is catalyzed by a multi-subunit form of the acetyl-CoA carboxylase enzyme (ACC). This enzyme carboxylates...
Nitrogen Starvation Acclimation in Synechococcus elongatus: Redox-Control and the Role of Nitrate Reduction as an Electron Sink.
Life (2075-1729) 5(1):888 (2015)
Nitrogen starvation acclimation in non-diazotrophic cyanobacteria is characterized by a process termed chlorosis, where the light harvesting pigments are degraded and the cells gradually tune down photosynthetic and metabolic activities. The chlorosis response is governed by a complex and poorly...
Phosphoproteome of the cyanobacterium Synechocystis sp. PCC 6803 and its dynamics during nitrogen starvation.
Frontiers in Microbiology 6:248 (2015)
Cyanobacteria have shaped the earth's biosphere as the first oxygenic photoautotrophs and still play an important role in many ecosystems. The ability to adapt to changing environmental conditions is an essential characteristic in order to ensure survival. To this end, numerous studies have show...
Metabolic pathway engineering using the central signal processor PII.
Microbial Cell Factories 14(1):192 (2015)
PII signal processor proteins are wide spread in prokaryotes and plants where they control a multitude of anabolic reactions. Efficient overproduction of metabolites requires relaxing the tight cellular control circuits. Here we demonstrate that a single point mutation in the PII signaling prote...
Energy Sensing versus 2-Oxoglutarate Dependent ATPase Switch in the Control of Synechococcus PII Interaction with Its Targets NAGK and PipX.
PLoS ONE 10(8):e0137114 (2015)
PII proteins constitute a superfamily of highly conserved signaling devices, common in all domains of life. Through binding of the metabolites ATP, ADP and 2-oxoglutarate (2-OG), they undergo conformational changes which allow them to regulate a variety of target proteins including enzymes, tran...
A Widespread Glutamine-Sensing Mechanism in the Plant Kingdom
Cell 159(5):1188 (2014)
Glutamine is the primary metabolite of nitrogen assimilation from inorganic nitrogen sources in microorganisms and plants. The ability to monitor cellular nitrogen status is pivotal for maintaining metabolic homeostasis and sustaining growth. The present study identifies a glutamine-se...
SPR analysis of promoter binding of Synechocystis PCC6803 transcription factors NtcA and CRP suggests cross-talk and sheds light on regulation by effector molecules.
FEBS Letters 588(14):2270 (2014)
Surface plasmon resonance monitoring of the binding of transcription factors cAMP receptor protein (CRP) and nitrogen control factor of cyanobacteria (NtcA) from Synechocystis sp. PCC6803 to promoter fragments of glnA, glnN (NtcA regulon) and cccS (CRP regulon), revealed exclusive CRP binding to...
Population shift of binding pocket size and dynamic correlation analysis shed new light on the anticooperative mechanism of PII protein.
Proteins: Structure, Function and Bioinformatics 82(6):1048 (2014)
PII protein is one of the largest families of signal transduction proteins in archaea, bacteria, and plants, controlling key processes of nitrogen assimilation. An intriguing characteristic for many PII proteins is that the three ligand binding sites exhibit anticooperative allosteric regulation...