Alternative mutations of a positively selected residue elicit gain or loss of functionalities in enzyme evolution.

ABSTRACT: All molecular species in an organism are connected physically and functionally to other molecules. In evolving systems, it is not obvious to what extent functional properties of a protein can change to selective advantage and leave intact favorable traits previously acquired. This uncertainty has particular significance in the evolution of novel pathways for detoxication, because an organism challenged with new xenobiotics in the environment may still require biotransformation of previously encountered toxins. Positive selection has been proposed as an evolutionary mechanism for facile adaptive responses of proteins to changing conditions. Here, we show, by saturation mutagenesis, that mutations of a hypervariable residue in human glutathione transferase M2-2 can differentially change the

SUBMITTER: Norrgard MA 

PROVIDER: S-EPMC1458763 | biostudies-literature | 2006 Mar

REPOSITORIES: biostudies-literature