Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The evolutionary history of a protein domain may date back further in time than that of the whole-gene ortholog that it is part of. Multidomain genes 3 and 4 originated around the same time. However, they are made up of two protein domains (blue and orange boxes) that emerged and diverged at different points in time—domain 1 is older than domain 2.
