1.45A resolution structure of Norovirus 3CL protease complex with a covalently bound dipeptidyl inhibitor (1R,2S)-2-({N-[(benzyloxy)carbonyl]-3-cyclohexyl-L-alanyl}amino)-1-hydroxy-3-[(3S)-2-oxopyrrolidin-3-yl]propane-1-sulfonic acid (Orthorhombic P Form)