The NTD contains sites for RNA binding. The RNA-binding sites on the NTD of N protein were identified by observing its interactions with ribonucleoside 5'-monophosphates (AMP, UMP, CMP, and GMP).[26] Using the information about interaction between AMP and UMP binding to the NTD of nucleocapsid protein, inhibitors of RNA binding were designed. Three-dimensional structure with all complex can see from PDB that is 4LMC, 4LM9, 4LM7, and 4LI4, respectively.[26] One such molecule which was designed with this strategy is N-(6-oxo-5,6-dihydrophenanthridine-2-yl) (N, N dimethyl amino) (PJ34), which was designed using the HCoV-OC43 model.[26] Binding of PJ34 on NTD affects the genome binding and replication process of CoV.[26] The crystal structure of COV-OC43 N-NTD with inhibitor PJ34 complex is given in PDB ID: 4KXJ.[26] On the basis of interactions between PJ34 and NTD of nucleocapsid protein, another inhibitor was designed that is H3 (6-chloro-7-(2-morpholin-4-yl-ethylamino) quinoxaline-5,8-dione), which also inhibits RNA binding.[2669] This highlights the importance of NTD in RNA binding. Some of the herbal products, such as catechin gallate and gallocatechin gallate (both are polyphenolic compounds), have shown the inhibitory action against SARS-CoV.[70]