[Chimera-users] Covalent bond making and docking

Good evening, I was trying to make a man made side chain, which is serine plus uracil. I used the command "bond sel" to connect the oxygen and nitrogen. Then I was trying to do docking to see if this mutation changed the binding affinity. However, after I ran dock prep, the uracil was got rid of because of "poor connection". I am wondering if this arbitrary bond is feasible in chimera and can I do docking with this artificial model? Thank you, Bixia