Abstract: It is intended to provide an extract, kit and a process for synthesizing a protein in a cell-free system. The extract is characterized by being prepared from mutant Escherichia coli cells having a mutation in the ribosomal protein S12 gene. In a preferred embodiment, the mutation is such a mutation as conferring a resistance or dependence to streptomycin on E. coli whereby the reading efficiency of mRNA codon on ribosomes can be improved and thus the protein productivity can be elevated.

Abstract: It is intended to provide an extract, kit and a process for synthesizing a protein in a cell-free system. The extract is characterized by being prepared from mutant Escherichia coli cells having a mutation in the ribosomal protein S12 gene. In a preferred embodiment, the mutation is such a mutation as conferring a resistance or dependence to streptomycin on E. coli whereby the reading efficiency of mRNA codon on ribosomes can be improved and thus the protein productivity can be elevated.

Abstract: It is intended to provide an extract, kit and a process for synthesizing a protein in a cell-free system. The extract is characterized by being prepared from mutant Escherichia coli cells having a mutation in the ribosomal protein S12 gene. In a preferred embodiment, the mutation is such a mutation as conferring a resistance or dependence to streptomycin on E. coli whereby the reading efficiency of mRNA codon on ribosomes can be improved and thus the protein productivity can be elevated.

Abstract: It is intended to provide a process for producing an extract for cell-free protein synthesis whereby the productivity of a protein and the production efficiency can be improved. Cells are cultured under suppressed growth conditions. In the stationary phase of the culture, the cells are collected and then disrupted. The above-described cells are preferably bacterial cells, in particular, Escherichia coli cells. In the suppressed growth conditions as described above, the culture temperature is preferably from 20 to 32° C., more preferably 26° C. or higher and lower than 30° C.

Abstract: It is intended to provide a process for producing an extract for cell-free protein synthesis whereby the productivity of a protein and the production efficiency can be improved. Cells are cultured under suppressed growth conditions. In the stationary phase of the culture, the cells are collected and then disrupted. The above-described cells are preferably bacterial cells, in particular, Escherichia coli cells. In the suppressed growth conditions as described above, the culture temperature is preferably from 20 to 32° C., more preferably 26° C. or higher and lower than 30° C.

Abstract: It is intended to provide a process for producing an extract for cell-free protein synthesis whereby the productivity of a protein and the production efficiency can be improved. Cells are cultured under suppressed growth conditions. In the stationary phase of the culture, the cells are collected and then disrupted. The above-described cells are preferably bacterial cells, in particular, Escherichia coli cells. In the suppressed growth conditions as described above, the culture temperature is preferably from 20 to 32° C., more preferably 26° C. or higher and lower than 30° C.

Abstract: It is intended to provide an extract, kit and a process for synthesizing a protein in a cell-free system. The extract is characterized by being prepared from mutant Escherichia coli cells having a mutation in the ribosomal protein S12 gene. In a preferred embodiment, the mutation is such a mutation as conferring a resistance or dependence to streptomycin on E. coli whereby the reading efficiency of mRNA codon on ribosomes can be improved and thus the protein productivity can be elevated.