The present invention provides, in various embodiments, genetically modified aerobic bacteria, polynucleotides and methods for expressing and/or harvesting electrically conductive protein nanowires (e-PNs). The present invention also provides e-PNs produced using the genetically modified aerobic bacteria, polynucleotides and methods.

The present invention provides, in various embodiments, genetically modified aerobic bacteria, polynucleotides and methods for expressing and/or harvesting electrically conductive protein nanowires (e-PNs). The present invention also provides e-PNs produced using the genetically modified aerobic bacteria, polynucleotides and methods.

Compositions and methods for efficiently producing and delivering double stranded RNA (dsRNA) are provided. Vector constructs useful for in vitro and in vivo expression of dsRNA are described. Also described are cell expression systems for efficient and cost-effective production of dsRNA in living cells and methods and compositions for providing the expressed dsRNA to target organisms. The described compositions and methods can be used to produce RNA molecules for screening or other uses, and to amplify RNA sequences for analysis.

Compositions and methods for efficiently producing and delivering double stranded RNA (dsRNA) are provided. Vector constructs useful for in vitro and in vivo expression of dsRNA are described. Also described are cell expression systems for efficient and cost-effective production of dsRNA in living cells and methods and compositions for providing the expressed dsRNA to target organisms. The described compositions and methods can be used to produce RNA molecules for screening or other uses, and to amplify RNA sequences for analysis.

The present disclosure relates, according to some embodiments, to compositions, methods, systems, and kits for programmable endonucleolytic cleavage of DNA (e.g., ds DNA). For example, the in vitro activity of an Argonaute (e.g., a mesophilic Argonaute CbAgo from Clostridium butyricum) may be synchronized with DNA strand unwinding activity of a helicase (e.g., a nuclease deficient RecB.sup.exo-C DNA helicase from E. coli) for a rapid and efficient cleavage of double-stranded DNA targets. Enzymatic properties of CbAgo and different aspects of ds DNA cleavage were thoroughly explored by adapting high-throughput capillary electrophoreses technique for monitoring CbAgo cleavage activity in concurrence with RecB.sup.exo-C. The present disclosure shows that in the presence of RecB.sup.exo-C, CbAgo can be programmed with guides to cleave any site of interest localized at up to 10 kb distance from the end of linear ds DNA at 37° C. temperature. CbAgo/RecB.sup.exo-C can be programmed to generate DNA fragments flanked with unique single-stranded extensions suitable for seamless ligation with compatible DNA fragments. The present disclosure relates further the compositions, methods, systems, and kits for PRC-free assembly of linear DNA molecules by using CbAgo/RecB.sup.exo-C programmable DNA endonuclease. The results presented here demonstrate that the combination of CbAgo and RecB.sup.exo-C is currently an efficient mesophilic DNA-guided DNA-cleaving programmable endonuclease which can be used to prepare synthetic biology tools that require or benefit from sequence-specific nicking/cleavage of natural DNA at otherwise inaccessible locations.

Methods and systems for autoinduction of gene expression, without the need to add exogenous inducers. A dual genetic element system, which includes a first, high copy number genetic element comprising a first gene of interest that is under the control of an inducible promoter, and a second, low copy number genetic element comprising a gene encoding a transcriptional factor which, upon expression, regulates transcription from the inducible promoter, wherein activation of transcription from the inducible promoter does not require addition of an exogenous inducer.

Methods and systems for autoinduction of gene expression, without the need to add exogenous inducers. A dual genetic element system, which includes a first, high copy number genetic element comprising a first gene of interest that is under the control of an inducible promoter, and a second, low copy number genetic element comprising a gene encoding a transcriptional factor which, upon expression, regulates transcription from the inducible promoter, wherein activation of transcription from the inducible promoter does not require addition of an exogenous inducer.

A protein expression system for use in a prokaryotic host is provided, the expression system comprising: a) an expression cassette comprising a nucleic acid sequence encoding a protein of interest operably linked to a T7 RNA polymerase-dependent promoter; and b) an expression cassette comprising a nucleic acid sequence encoding T7 RNA polymerase operably linked to a host polymerase-dependent λ phage promoter and a single perfect palindrome operator sequence; wherein the expression cassette for T7 RNA polymerase is located on the chromosome of a host cell.

A protein expression system for use in a prokaryotic host is provided, the expression system comprising: a) an expression cassette comprising a nucleic acid sequence encoding a protein of interest operably linked to a T7 RNA polymerase-dependent promoter; and b) an expression cassette comprising a nucleic acid sequence encoding T7 RNA polymerase operably linked to a host polymerase-dependent λ phage promoter and a single perfect palindrome operator sequence; wherein the expression cassette for T7 RNA polymerase is located on the chromosome of a host cell.

Compositions and methods for efficiently producing and delivering double stranded RNA (dsRNA) are provided. Vector constructs useful for in vitro and in vivo expression of dsRNA are described. Also described are cell expression systems for efficient and cost-effective production of dsRNA in living cells and methods and compositions for providing the expressed dsRNA to target organisms. The described compositions and methods can be used to produce RNA molecules for screening or other uses, and to amplify RNA sequences for analysis.