This invention provides a recombinant protein expression system using a host and cell-free translation system, and is capable of universally expressing a large amount of any protein as soluble protein, while preventing toxicity in hosts, formation of inclusion bodies, and decompositions with proteases. Such may be achieved by expressing the desired protein as a fusion protein with chaperoning, such as about 60 kDa molecular chaperons, 60 kDa heat shock proteins, or thermosomes, and accommodating...