If I understand your question correctly, youre asking "how different
do two structures need to be for one to be "new'". If by "new" you
mean a new fold, then the answer is NO. Your structure and the homolog
have the same fold.
However, if your structure is the first structure of a protein in a
new class, then your structure is a new insight for that reason (e.g.
it is the first structure of a Unobtainium-metalloprotease).
If it is not the first structure of a protein from a new class, lets
say a previous structure of Unobtainium-metalloprotease has been
solved using H. sapiens' sequence, but your protein is the first D.
melanogaster ortholog solved, then your structure is a new insight for
So, in a nut-shell, I guess what I am saying is that your protein is
not a new fold, but is almost certainly "new" by some qualification,
and you will know best what that qualification is. I hope that helps,
cheers and happy holidays~
On 20/12/2010 10:49, <Liu Zhao > wrote:
The structure of my protein is as shown as the purple one. Another one
,as shown as green,is homologous .But the structure of my protein can't
be obtained by using molecular replacement. And both structures have
much different, especially in B chain. If my structure is a new one?
thank you for help.