CELL EXTRACT OF ESCHERICHIA COLI HAVING A MUTATION IN THE S12 RIBOSOMAL PROTEIN AND PROCESS FOR PRODUCING PROTEINS IN CELL-FREE SYSTEMES

摘要

It is intended to provide an extract, kit and a process for synthesizing a protein in a cell-free system. The extract is <Bold>characterized by</Bold> 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 <Italic>E. coli</Italic> whereby the reading efficiency of mRNA codon on ribosomes can be improved and thus the protein productivity can be elevated.