Hi: this must be an old problem but I would like to know if there are other ideas to make things easier.
I solved a structure that contains 240 helices of identical sequences in the asymmetric unit. Handling so many chains is really a headache as pdb contains only a single column for chain ID (currently support up to 61 chains). I had to combine some (say a tetramer) as a single chain for a trick, which made me use just enough letters/numbers (A-Z,1-9,a-z). However this will need further manual dealing with OXTs (currently I cheat with single N of a residue) and raise new problems (like restraints). Some softwares does even not recognize chain IDs like a-z. SegID might be another trick however nowadays many softwares won't take that part, so a down-to-chain rigid body / TLS refinement could be impossible, without the combination trick. With tricks I am ok to make things going? But is there a solution really solve the many-chain problem with PDB? Best, Lijun Sent from my iPhone
