The enzymatic activity of glutamine synthetase (GS) which is a major enzyme assimilating nitrogen in enteric bacteria is modulated by a bicyclic cascade that consists in adenylylation / deadenylylation of GS and uridylylation / deuridylylation of a re...
The enzymatic activity of glutamine synthetase (GS) which is a major enzyme assimilating nitrogen in enteric bacteria is modulated by a bicyclic cascade that consists in adenylylation / deadenylylation of GS and uridylylation / deuridylylation of a regulatory protein PII. The adenylylation of GS converts the enzyme to an inactive form. The cunverter enzyme for the adenylylation / deadenylylation cycle is adenylyltransferase (AT), a bifunctional enzyme. It is known that many of regulatory proteins of GS are affected by the nitrogen content in medium.
In this study, glnE gene sequence from BamHI to Sali restriction site was determined to elucidate the possibility of its nitrogen sensing ability by searching the consensus sequence(WGCA) found in other nitrogen utilizing operons.
The results are as follows ; 1) The nucleotide length of a part of glnE gene was 1203 dp and the initial codon ATG was determined by comparing the sequence with 13 amino acid residues from N-terminus of AT. 2) The probable consensus sequence TTGCA showing high homology with those of other nitrogen utilizing operons was found at 43 bp upstream region from the start point.
Actual nitrogen sensing capability of glnE gene should be tested to find the complex regulatory mechanism of GS cascade system for further study.