The invention provides a chimeric enzyme comprising at least one catalytic domain of a RNA triphosphatase, at least one catalytic domain of a guanylyltransferase, at least one catalytic domain of a N 7 -guanine methyltransferase, and at least one catalytic domain of a DNA-dependant RNA polymerase. The invention also provides pharmaceutical composition comprising said chimeric enzyme and uses of said chimeric enzyme.
