Open AccessStructure of isochorismate synthase in complex with magnesium
Author(s) -
Parsons James F.,
Shi Katherine M.,
Ladner Jane E.
Publication year - 2008
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444908005477
Subject(s) - nucleophile , chemistry , stereochemistry , isomerization , crystal structure , active site , molecule , transferase , magnesium , substrate (aquarium) , enzyme , catalysis , crystallography , biochemistry , organic chemistry , biology , ecology
The electron carrier menaquinone is one of many important bacterial metabolites that are derived from the key intermediate chorismic acid. MenF, the first enzyme in the menaquinone pathway, catalyzes the isomerization of chorismate to isochorismate. Here, an improved structure of MenF in a new crystal form is presented. The structure, solved at 2.0 Å resolution in complex with magnesium, reveals a well defined closed active site. Existing evidence suggests that the mechanism of the reaction catalyzed by MenF involves nucleophilic attack of a water molecule on the chorismate ring. The structure reveals a well defined water molecule located in an appropriate position for activation by Lys190 and attack on the substrate.