J. Biol. Chem., Vol. 268, Issue 32, 24242-24246, 11, 1993
Expression of glr (murI, dga) gene encoding glutamate racemase in Escherichia coli [published erratum appears in J Biol Chem 1994 Jun 17;269(24):16983]
T Yoshimura, M Ashiuchi, N Esaki, C Kobatake, SY Choi and K Soda
Institute for Chemical Research, Kyoto University, Japan.
The murI (dga) gene of Escherichia coli is required for the biosynthesis of
D-glutamate, an essential component of bacterial peptidoglycan (Doublet,
P., van Heijetnoort, J., and Mengin-Lecreulx, D. (1992) J. Bacteriol. 174,
5772-5779; Dougherty, T. J., Thanassi, J. A., and Pucci, M. J. (1993) J.
Bacteriol. 175, 111-116), but its gene product has not been identified. We
found that the amino acid sequence of protein deduced from the nucleotide
sequence of the open reading frame of murI gene (ORF1) shows a significant
homology with that of glutamate racemase of Pediococcus pentosaceus. The
amino acid sequence of glutamate racemase of Lactobacillus fermenti
recently reported also shows a homology with the deduced amino acid
sequence of ORFI (Gallo, K. A., and Knowles, J. R. (1993) Biochemistry 32,
3981-3990). The murI (dga) gene was ligated into a plasmid, pKK223-3, with
a designed ribosome binding site and expressed in E. coli JM109 cells.
Glutamate racemase was produced by the transformant cells, whereas the
enzyme was not found in the host cells. Accordingly, we newly termed the
gene glr, which is more relevant than murI and dga. We partially purified
the enzyme to characterize it. The enzyme consists of two identical
subunits with a molecular weight of about 31,000 in contrast to the P.
pentosaceus enzyme, a monomer protein.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
