Duplorna-fold (BTV fold)
The T2 fold assembles in T=2* capsids with dimer of two conformers and consists of a complex arrangement domains .
All capsid proteins have a the same topology from N to C-terminus: -The linker region interacts with neighboring capsid protein dimer and form a belt that stabilizes the shell. -The column runs from top to bottom and connects the other domains. It essentially consists of beta strands; -The apical domain consists mainly of alpha-helixes, which form the five-fold pore of the capsid. In many ghabrivirales it contains a loop having the cap-snatching catalytic activity. -The carapace domain varies in size between Reovirales, ghabrivirales and mindivirales. - The dimerization domain consists mainly of beta-strands, except in mindivirales, which are mainly alpha-helixes. It is flexible and forms the three-fold axes and the two-fold axes of the icosahedral capsid.
Origin:
Viral