| abstract |
Provided in the present invention is an asparaginic acid kinase, and the 340th amino acid residue in the position of the amino acid sequence of the asparaginic acid kinase corresponding to the amino acid sequence shown in SEQ ID NO:2 is a non-aspartic acid. The asparaginic acid of the present invention can efficiently relieve the feedback inhibition of L-lysine, and can be effectively used for the production of L-lysine. Also provided in the present invention are host cells comprising genes coding the asparaginic acid kinase and a method for producing L-lysine using the host cells or the asparaginic acid kinase. The asparaginic acid kinase of the present invention or the host cells comprising the asparaginic acid kinase of the present invention is also used to procuce L-threonine, L-methionine, L-isoleucine or L-valine. Also provided in the present invention is a method of producing L-aspartyl-4-yl phosphoric acid using the asparaginic acid kinase or the host cells. |