The present invention relates to a fusion protein for enhancing expression efficiency of a target protein. More specifically, the present invention relates to a glutamyl-prolyl-tRNA synthetase from human (hEPRS) WHEP domain (including WHEP domains TRS-1, TRS-2, and TRS-3 which locate at middle sites of the EPRS protein, and linkers connecting the three domains therethrough). When used as a fusion protein for expressing a target protein in E. coli, the hEPRS WHEP domain according to the present invention enhanced water solubility of the target protein.

The present invention relates to an EPRS (glutamyl-prolyl-tRNA synthetase) protein or a fragment thereof. The EPRS protein of the present invention or fragment thereof may bind to PCBP2 protein to activate the MAVS signaling pathway, and thus it has anti-RNA viral effects, thereby being effective for preventing or treating a RNA viral infectious disease.

Provided is a heterocyclic amide compound that may have a PRS inhibitory action and is expected to be useful as a prophylactic or therapeutic agent for PRS associated diseases and the like including cancer. A compound represented by the following formula (I): ##STR00001##
wherein each symbol is as described in the DESCRIPTION, or a salt thereof.

Provided is a heterocyclic amide compound that may have a PRS inhibitory action and is expected to be useful as a prophylactic or therapeutic agent for PRS associated diseases and the like including cancer. A compound represented by the following formula (I):

##STR00001##

wherein each symbol is as described in the DESCRIPTION, or a salt thereof.

The present invention relates to an EPRS (glutamyl-prolyl-tRNA synthetase) protein or a fragment thereof.

The EPRS protein of the present invention or fragment thereof may bind to PCBP2 protein to activate the MAVS signaling pathway, and thus it has anti-RNA viral effects, thereby being effective for preventing or treating a RNA viral infectious disease.