Crystal structure of wild-type HIV-1 protease with a novel HIV-1 inhibitor GRL-14213A of 6-5-5-ring fused crown-like tetrahydropyranofuran as the P2-ligand, a cyclopropylaminobenzothiazole as the P2\'-ligand and 3,5-difluorophenylmethyl as the P1-ligand
