In: Biology
I know homologous proteins will have similar structures, but will non-homologous proteins with similar functions also have similar structures?
Proteins are said to be homologous if they have a common ancestor.
Non-homologous proteins come from different ancestral families. If they have similar function, there is a high probability for them to also have a similar structure. Because of different ancestors, they would probably not have similar sequences, but due to similar function, structure may be similar. Proteins fold in a structure which can support the function of the protein. The fold is characteristic of domains, which will facilitate the function. For example, dehydrogenases from any organism are expected to have the Rossmann fold, to allow cofactor binding, thus similarities in the structure. Thus, percentage of structural similarity would be lower in non-homologous proteins when compared to homologous proteins, but their similar function will drive them to have essential structural elements to support the function to remain similar.
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