Abstract: The “instant evolution” system was initially developed in E. coli, primarily because of the ease with which this organism can be genetically manipulated. Because many of the functionally important regions of rRNA are conserved among bacteria, drug leads developed against conserved targets in the E. coli system may produce broad-spectrum anti-infectives. In order to develop a system to produce narrow-spectrum anti-infectives, herein we disclose methods for identifying functional mutant P. aeruginosa ribosomes suitable as drug targets and for identifying drug candidates that do not bind to the human 16S rRNA.

Abstract: Provided are methods and compositions for in vivo display and screening of peptides for antimicrobial activity. The methods can include expressing a random peptide library in a microbial cell culture and identifying clones in which microbial cell growth or survival is affected by the peptide expressed by that clone. Also provided are peptide antimicrobials identified using these methods and compositions.

Abstract: The “instant evolution” system was initially developed in E. coli, primarily because of the ease with which this organism can be genetically manipulated. Because many of the functionally important regions of rRNA are conserved among bacteria, drug leads developed against conserved targets in the E. coli system may produce broad-spectrum anti-infectives. In order to develop a system to produce narrow-spectrum anti-infectives, herein we disclose methods for identifying functional mutant P. aeruginosa ribosomes suitable as drug targets and for identifying drug candidates that do not bind to the human 16S rRNA.

Abstract: The “instant evolution” system was initially developed in E. coli, primarily because of the ease with which this organism can be genetically manipulated. Because many of the functionally important regions of rRNA are conserved among bacteria, drug leads developed against conserved targets in the E. coli system may produce broad-spectrum anti-infectives. In order the develop a system to product narrow-spectrum anti-infectives, herein we disclose methods for identifying functional mutant P. aeruginosa ribosomes suitable as drug targets and for identifying drug candidates that do not bind to the human 16S rRNA.

Abstract: To identify conserved and variable regions of the 16 S rRNA, an instant evolution experiment was performed on the entire 16 S rRNA. Analysis of these mutants identified regions that are required for function. These conserved sequences may be used as targets for pharmaceuticals that are taxonomically specific and which are refractory to the development of drug resistance.

Abstract: Compositions are provided to identify functional mutant ribosomes that may be used as drug targets. The compositions allow isolation and analysis of mutations that would normally be lethal and allow direct selection of rRNA mutants with predetermined levels of ribosome function. The compositions of the present invention may be used to identify antibiotics to treat a large number of human pathogens through the use of genetically engineered rRNA genes from a variety of species. The invention further provides novel plasmid constructs to be used in the methods of the invention.

Abstract: The “instant evolution” system was initially developed in E. coli, primarily because of the ease with which this organism can be genetically manipulated. Because many of the functionally important regions of rRNA are conserved among bacteria, drug leads developed against conserved targets in the E. coli system may produce broad-spectrum anti-infectives. In order the develop a system to product narrow-spectrum anti-infectives, herein we disclose methods for identifying functional mutant P. aeruginosa ribosomes suitable as drug targets and for identifying drug candidates that do not bind to the human 16S rRNA.

Abstract: To identify conserved and variable regions of the 16 S rRNA, an instant evolution experiment was performed on the entire 16 S rRNA. Analysis of these mutants identified regions that are required for function. These conserved sequences may be used as targets for pharmaceuticals that are taxonomically specific and which are refractory to the development of drug resistance.

Abstract: Provided are methods and compositions for in vivo display and screening of peptides for antimicrobial activity. The methods can include expressing a random peptide library in a microbial cell culture and identifying clones in which microbial cell growth or survival is affected by the peptide expressed by that clone. Also provided are peptide antimicrobials identified using these methods and compositions.

Abstract: Described herein are methods of screening one of the RNA hairpins in the small ribosomal subunit of bacteria to identify peptides that bind to it. The RNA hairpin target may be the 970 loop (aka helix 31 (h31)) or a modified version thereof. The identified peptides may inhibit protein synthesis and, therefore, may be used as a model for new antibiotics.

Abstract: The “instant evolution” system was initially developed in E. coli, primarily because of the ease with which this organism can be genetically manipulated. Because many of the functionally important regions of rRNA are conserved among bacteria, drug leads developed against conserved targets in the E. coli system may produce broad-spectrum anti-infectives. However, in order the develop a system to product narrow-spectrum anti-infectives, herein we disclose method and compositions for screening Pseudomonas aeruginosa 16S rRNA in E. coli cells. In certain embodiments, a plasmid comprising the 16S rRNA gene from Pseudomonas aeruginosa t mutated to replace the natural helix 9 region with the corresponding region of the E. coli rRNA, is shown to form functional ribosomes in E. coli host cells. Li other embodiments, a plasmid, comprising the unmutated 16S rRNA from Pseudomonas aeruginosa, along with a plasmid containing the Pseudomonas aeruginosa S20 protein, can yield functional ribosomes in E. coli cells.

Abstract: To identify conserved and variable regions of the 16 S rRNA, an instant evolution experiment was performed on the entire 16 S rRNA. Analysis of these mutants identified regions that are required for function. These conserved sequences may be used as targets for pharmaceuticals that are taxonomically specific and which are refractory to the development of drug resistance.

Abstract: Described herein are methods of screening one of the RNA hairpins in the small ribosomal subunit of bacteria to identify peptides that bind to it. The RNA hairpin target may be the 970 loop (aka helix 31 (h31)) or a modified version thereof. The identified peptides may inhibit protein synthesis and, therefore, may be used as a model for new antibiotics.

Abstract: Compositions and methods are provided to identify functional mutant ribosomes that may be used as drug targets. The compositions and methods allow isolation and analysis of mutations that would normally be lethal and allow direct selection of rRNA mutants with predetermined levels of ribosome function. The compositions and methods of the present invention may be used to identify antibiotics to treat a large number of human pathogens through the use of genetically engineered rRNA genes from a variety of species. The invention further provides novel plasmid constructs to be used in the methods of the invention.

Abstract: To identify conserved and variable regions of the 16 S rRNA, an instant evolution experiment was performed on the entire 16 S rRNA. Analysis of these mutants identified regions that are required for function. These conserved sequences may be used as targets for pharmaceuticals that are taxonomically specific and which are refractory to the development of drug resistance.

Abstract: The “instant evolution” system was initially developed in E. coli, primarily because of the ease with which this organism can be genetically manipulated. Because many of the functionally important regions of rRNA are conserved among bacteria, drug leads developed against conserved targets in the E. coli system may produce broad-spectrum anti-infectives. However, in order the develop a system to product narrow-spectrum anti-infectives, herein we disclose method and compositions for screening Pseudomonas aeruginosa 16S rRNA in E. coli cells. In certain embodiments, a plasmid comprising the 16S rRNA gene from Pseudomonas aeruginosa t mutated to replace the natural helix 9 region with the corresponding region of the E. coli rRNA, is shown to form functional ribosomes in E. coli host cells. Li other embodiments, a plasmid, comprising the unmutated 16S rRNA from Pseudomonas aeruginosa, along with a plasmid containing the Pseudomonas aeruginosa S20 protein, can yield functional ribosomes in E. coli cells.

Abstract: A continuous wave photolytic iodine laser has a gain cell for receiving a continuous supply of gaseous fuel. The gain cell is connected to laser beam transfer optics, a laser resonator for shaping a laser beam, and a lamp. The lamp is driven by a microwave subsystem such that a laser gain medium is pumped through the gain cell. The continuous wave photolytic iodine laser of the present invention incorporates a closed loop fuel system for presenting gaseous fuel to the gain cell at a rate sufficient to sweep any lasing by-products out of the gain cell, thereby preventing quenching of the lasing process. The fuel system also includes a condenser for converting the gaseous fuel to a liquid after it has passed through the gain cell, a scrubber for removing the by-products of the lasing process from the fuel, and an evaporator for converting the recycled liquefied fuel back to a gas. The closed loop fuel system also includes a pump for pressurizing and transporting the liquefied fuel.

Abstract: A continuous wave photolytic iodine laser has a gain cell for receiving a continuous supply of gaseous fuel. The gain cell is connected to laser beam transfer optics, a laser resonator for shaping a laser beam, and a lamp. The lamp is driven by a microwave subsystem such that a laser gain medium is pumped through the gain cell. The continuous wave photolytic iodine laser of the present invention incorporates a closed loop fuel system for presenting gaseous fuel to the gain cell at a rate sufficient to sweep any lasing by-products out of the gain cell, thereby preventing quenching of the lasing process. The fuel system also includes a condenser for converting the gaseous fuel to a liquid after it has passed through the gain cell, a scrubber for removing the by-products of the lasing process from the fuel, and an evaporator for converting the recycled liquefied fuel back to a gas. The closed loop fuel system also includes a pump for pressurizing and transporting the liquefied fuel.

Abstract: A continuous wave photolytic iodine laser has a gain cell for receiving a continuous supply of gaseous fuel. The gain cell is connected to laser beam transfer optics, a laser resonator for shaping a laser beam, and a lamp. The lamp is driven by a microwave subsystem such that a laser gain medium is pumped through the gain cell. The continuous wave photolytic iodine laser of the present invention incorporates a closed loop fuel system for presenting gaseous fuel to the gain cell at a rate sufficient to sweep any lasing by-products out of the gain cell, thereby preventing quenching of the lasing process. The fuel system also includes a condenser for converting the gaseous fuel to a liquid after it has passed through the gain cell, a scrubber for removing the by-products of the lasing process from the fuel, and an evaporator for converting the recycled liquefied fuel back to a gas. The closed loop fuel system also includes a pump for pressurizing and transporting the liquefied fuel.

Abstract: A laser with an unstable resonator configuration is described with a second, lower power auxiliary laser to provide a feedback beam to pulse high power CW lasers without exceeding the power handling capability limitation of currently available modulators. The present laser relies on adjoint mode feedback provided by the auxiliary laser to accomplish pulsed operation with a modulator in the low power feedback beam path. Higher power output beams can be generated with multiple stages of auxiliary laser providing adjoint mode feedback, thereby reducing incident power on modulation devices while providing adequate adjoint beam power to effectively pulse the high power laser. In certain embodiments a single gain generator is used to drive the main and auxiliary lasers.