Patent ID: 7785860
Filing Date: 2010-08-31
Classification: C12N,C12P

Abstract:
1. An isolated L-histidine producing bacterium of the Enterobacteriaceae family which has been modified to have enhanced activity of Escherichia AICAR transformylase-IMP cyclohydrolase as compared to said bacterium of the Enterobacteriaceae family which is non-modified, wherein said activity is enhanced by increasing the expression of the AICAR transformylase-IMP cyclohydrolase gene by a method selected from the group consisting of: (a) increasing the copy number of the AICAR transformylase-IMP cyclohydrolase gene, and (b) placing the AICAR transformylase-IMP cyclohydrolase gene under the control of a more potent promoter instead of the native promoter; and wherein said bacterium is able to produce not less than 1.0 g/L of L-histidine, wherein said L-histidine producing bacterium expresses a gene encoding ATP phosphoribosyl transferase which is desensitized to feedback inhibition by L-histidine, and wherein said AICAR transformylase-IMP cyclohydrolase gene encodes a protein selected from the group consisting of: (A) a protein comprising the amino acid sequence shown in SEQ ID NO: 2; and (B) a protein variant of the amino acid sequence shown in SEQ ID NO: 2 wherein said variant is at least 95% homologous with SEQ ID NO: 2 and has AICAR transformylase-IMP cyclohydrolase activity.