Open AccessExpression, purification and preliminary X‐ray analysis of crystals of Bacillus subtilis glutamate racemase
Author(s) -
Taal Makie A.,
Sedelnikova Svetlana E.,
Ruzheinikov Sergey N.,
Baker Patrick J.,
Rice David W.
Publication year - 2004
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444904021134
Subject(s) - bacillus subtilis , glutamate receptor , chemistry , biochemistry , microbiology and biotechnology , biology , bacteria , genetics , receptor
Glutamate racemase (MurI, RacE; E.C.5.1.1.3) catalyses the cofactor‐independent conversion of l ‐glutamate to d ‐glutamate, an essential step in the synthesis of components of the bacterial cell wall. The gene for RacE from Bacillus subtilis has been cloned and the protein expressed in Escherichia coli , purified and crystallized in the presence of l ‐glutamate using the hanging‐drop method of vapour diffusion with diammonium tartrate as the precipitant. The crystals belong to the monoclinic space group C 2, with approximate unit‐cell parameters a = 133.6, b = 60.1, c = 126.2 Å, β = 117.6°. Consideration of the possible values of V M suggests that the asymmetric unit contains either two ( V M = 3.75 Å 3 Da −1 ) or three ( V M = 2.5 Å 3 Da −1 ) subunits. The crystals diffract X‐rays to at least 2.1 Å resolution on a synchrotron‐radiation source and are suitable for structural studies. Determination of the structure may provide insight into the molecular basis of substrate recognition and catalysis by this enzyme.