Advances in DNA molecular evolution.

Directed molecular evolution and combinatorial methodologies are playing an increasingly important role in the in vitro evolution engineering of protein.It can dramatically optimize the sequence of single gene,plasmid,metabolic pathway,partial and even the whole genome of some organisms and generate new characteristic gene,protein or species which can not be generated by natural evolution.This review summarizes the principles,characteristics,progress and re-search direction of DNA molecular evolution methodologies,which would have wide application on increasing the specific activity of enzyme,the yield of protein,improving the functions of protein(enzyme),and so on.