POLYPEPTIDE FRAGMENTS HAVING ENDONUCLEASE ACTIVITY AND THEIR USE

摘要

PROBLEM TO BE SOLVED: To provide a polypeptide fragment or a variant thereof in which the PA subunit of a viral RNA dependent RNA polymerase having an endonuclease activity is derived from a virus belonging to Orthomyxoviridae.SOLUTION: The amino terminal fragment of the PA subunit has at least 90% sequence identity to a specific amino terminal fragment or the full length of the fragment, and holds an endonuclease activity. This invention relates to (i) crystals of the polypeptide fragments which are suitable for structure determination of the polypeptide fragments using X-ray crystallography, and (ii) methods using the structural coordinates of the polypeptide to screen for and identify compounds that modulate, preferably inhibit the endonucleolytically active site within the polypeptide fragment.