you can read this paper

Article Protein-Like Structure and Activity in Synthetic Polymers

you can read this paper

Article Protein-Like Structure and Activity in Synthetic Polymers

If you write "most of the available pdbs for protein are considering tetramer as a single polymer" do you mean that those template structures are indeed of proteins that do not form tetramers, or are the tetramers in the crystal oriented such that their symmetry axes coincide with crystallographic symmetry, and you only see a monomer in the asymmetric unit?

Mam

PDBs have a section called BIOMT having crystal symmetry. Ideally for a tetramer there should be entries for each monomer individually. But I am not getting those entries for each protein chain. There is single entry for complete tetramer. Hence can't use matrix based transformation.

I can visualize a tetramer but it doesn't have entry for each monomer.

If you can visualise the tetramer, you can least-square fit a copy of your model to each of the four monomers in the tetramer to obtain a tetramer of your model.

Can you give me some reference or tutorial link?

Which visualisation program are you using?

Assuming you have a tetramer structure, in which the individual monomers carry the chain label A,B,C and D respectively, and four copies of your monomer mono1, mono2, mono3 and mono4, in which the chain label is A

e.g. in PyMOL you would do the following, using the command line:

cealign /tetramer//A, /mono1//A

cealign /tetramer//B, /mono2//A

cealign /tetramer//C, /mono3//A

cealign /tetramer//D, /mono4//A

since you want the four monomers to have different chain labels in the tetramer model, you need to change the chain labels before merging them into one object:

alter /mono2//A, chain="B"

alter /mono3//A, chain="C"

alter /mono4//A, chain="D"

you can now merge them into one object:

create tetraModel, mono1 mono2 mono3 mono4

alternatively, you can directly save the four monomers in their final relative orientation into one pdb file:

save tetraModel.pdb, mono1 mono2 mono3 mono4

Other molecular visualisation programs usually contain the same functionalities of being able to align two molecules, and saving several molecular objects into one pub file. Consult the corresponding manual to find out how to do the same in the program you are using.

Thank you mam it worked, but I think there might be some clashes in bonds. Will you recommend a minimisation run on the tetramer?