why thymine shows protein diamer?

Answer 1

what?
are you talking about thymine dimers?
when DNA gets exposed to UV light, thymine dimers can form between adjacent thymines on the DNA molecule. This is a form of DNA damage.
So remember when you go outside in the summer, wear your sunscreen!!!

Answer 2

Thymine is nucleic acid, so it's really not involved with proteins. I'm not sure what you're asking here. If you're asking about thymine dimers, they occur from UV damage- the energy of the UV light causes two adjacent thymine bases to dimerize, leading to mutations in DNA.