DNA ENCODING DIPEPTIDE-SYNTHESIZING ENZYME (VARIANTS), BACTERIUM BELONGING TO THE GENUS ESCHERICHIA, AND METHODS FOR PRODUCING DIPEPTIDES USING THEREOF

摘要

The present invention describes novel bacterial L-amino acids α-ligases, which catalyzing reaction of dipeptide formation having an acidic L-amino acid such as L-Asp or L-Glu at the N-terminus. The method for producing dipeptides using said L-amino acids α-ligases and a bacterium of the family Enterobacteriaceae, particularly a bacterium belonging to the genus Escherichia, which has been modified to contain the DNA encoding said L-amino acids α-ligases, is described.

主权项

1. A DNA encoding a protein having dipeptide-synthesizing activity, wherein said DNA is selected from the group consisting of:
(A) a DNA having the nucleotide sequence of SEQ ID NOs: 1, 3 and 5; (B) a DNA hybridizing under stringent conditions with the nucleotide sequence complementary to the sequence shown in SEQ ID NOs: 1, 3 and 5, wherein said stringent conditions comprise washing one time or more in a solution containing a salt concentration of 1×SSC, 0.1% SDS or 0.1×SSC, 0.1% SDS at 60° C. or 65° C.; (C) a DNA encoding a protein having the amino acids sequence of SEQ ID NOs: 2, 4 and 6; (D) a DNA encoding a variant protein having the amino acid sequence of SEQ ID NOs: 2, 4 and 6, but which includes substitution, deletion, insertion, or addition of one or several amino acid residues and has dipeptide-synthesizing activity according to the amino acid sequence of SEQ ID NOs: 2, 4 and 6; and (E) a DNA encoding a protein having homology, defined in |Log 10(E-value)|-values, of not less than 128, not less than 142, not less than 162, not less than 175, not less than 182, not less than 196, or not less than 233 to the amino acids sequence of SEQ ID NOs: 2, 4 and 6, and dipeptide-synthesizing activity according to the amino acid sequence of SEQ ID NOs: 2, 4 and 6.