Apo and Aβ46-bound γ-secretase structures provide insights into amyloid-β processing by the APH-1B isoform.

Deposition of amyloid-β (Aβ) peptides in the brain is a hallmark of Alzheimer's disease. Aβs are generated through sequential proteolysis of the amyloid precursor protein by the γ-secretase complexes (GSECs). Aβ peptide length, modulated by the Presenilin (PSEN) and APH-1 subunits of GSEC, is critical for Alzheimer's pathogenesis.

Enhanced protein secretion in reduced genome strains of Streptomyces lividans.

Background: S. lividans TK24 is a popular host for the production of small molecules and the secretion of heterologous protein. Within its large genome, twenty-nine non-essential clusters direct the biosynthesis of secondary metabolites.

Extensive Reannotation of the Genome of the Model Streptomycete TK24 Based on Transcriptome and Proteome Information.

TK24 is a relevant Gram-positive soil inhabiting bacterium and one of the model organisms of the genus . It is known for its potential to produce secondary metabolites, antibiotics, and other industrially relevant products. TK24 is the plasmid-free derivative of 66 and a close genetic relative of the strain A3(2).

A contradictory action of procoagulant ficin by a fibrinolytic serine protease from Egyptian latex.

is one of the most popular and edible plants. Its trees emanate latex of high medical importance. The well-studied procoagulant effect of ficin is a hallmark of this latex which protrudes an interesting question of how can the plant control this effect? In the present work, we purified and characterized a serine protease (FPIII) with fibrinolytic activity from latex and study the anticoagulant character of the latex.

Characterization of Sigma Factor Genes in TK24 Using a Genomic Library-Based Approach for Multiple Gene Deletions.

Alternative sigma factors control numerous aspects of bacterial life, including adaptation to physiological stresses, morphological development, persistence states and virulence. This is especially true for the physiologically complex actinobacteria. Here we report the development of a robust gene deletions system for TK24 based on a BAC library combined with the λ-Red recombination technique.

Monitoring Protein Secretion in Using Fluorescent Proteins.

Fluorescent proteins are a major cell biology tool to analyze protein sub-cellular topology. Here we have applied this technology to study protein secretion in the Gram-positive bacterium TK24, a widely used host for heterologous protein secretion biotechnology. Green and monomeric red fluorescent proteins were fused behind Sec (SP) or Tat (SP) signal peptides to direct them through the respective export pathway.

Secretome Dynamics in a Gram-Positive Bacterial Model.

Protein secretion is a central biological process in all organisms. Most studies dissecting bacterial secretion mechanisms have focused on Gram-negative cell envelopes such as that of However, proteomics analyses in Gram negatives is hampered by their outer membrane. Here we studied protein secretion in the Gram-positive bacterium TK24, in which most of the secretome is released in the growth medium.

Streptomyces protein secretion and its application in biotechnology.

Bacteria are of tremendous importance in the pharma- and bio-industry as producers of a broad range of economically interesting metabolites and proteins. Gram-positive bacteria are valuable hosts for the production of heterologous proteins for obvious reasons. Contrary to Gram-negative bacteria, Gram-positive bacteria release their secreted proteins immediately into the spent culture broth as they are not hindered by an outer membrane.

Multi-Omics and Targeted Approaches to Determine the Role of Cellular Proteases in Protein Secretion.

Gram-positive bacteria are profuse secretors of polypeptides using complex, yet unknown mechanisms. Many of their secretory proteins are proteases that play important roles in the acquisition of amino acids from the environment. Other proteases regulate cellular proteostasis.

Large-scale production of a thermostable Rhodothermus marinus cellulase by heterologous secretion from Streptomyces lividans.

Background: The gene encoding a thermostable cellulase of family 12 was previously isolated from a Rhodothermus marinus through functional screening. CelA is a protein of 260 aminoacyl residues with a 28-residue amino-terminal signal peptide. Mature CelA was poorly synthesized in some Escherichia coli strains and not at all in others.

Fast and reliable strain characterization of Streptomyces lividans through micro-scale cultivation.

Filamentous organisms of the genus Streptomyces play an important role in industrial production processes, due to their extensive secondary metabolism variability, as well as their ability to secrete efficiently large amounts of (heterologous) proteins. While genetic engineering tools are available to rapidly build up large strain libraries, the subsequent strain screening and bioprocess development still constitutes a bottleneck. This is due to the lack of reliable parallelized and accelerated cultivation techniques for morphologically challenging organisms.