The structure of Synechococcus elongatus enolase reveals key aspects of phosphoenolpyruvate binding

GONZALEZ, JAVIER M.; MARTÍ-ARBONA, RICARDO; CHEN, JULIAN C.-H.; UNKEFER, CLIFFORD J.

Acta Crystallographica Section F Structural Biology Communications

WILEY-BLACKWELL PUBLISHING, INC

Año: 2022 vol. 78 p. 177 - 184

A structure-function characterization of Synechococcus elongatus enolase (SeEN) is presented, representing the first structural report on a cyanobacterial enolase. X-ray crystal structures of SeEN in its apoenzyme form and in complex with phosphoenolpyruvate are reported at 2.05 and 2.30 Å resolution, respectively. SeEN displays the typical fold of enolases, with a conformationally flexible loop that closes the active site upon substrate binding, assisted by two metal ions that stabilize the negatively charged groups. The enzyme exhibits a catalytic efficiency of 1.2 × 105 M−1 s−1 for the dehydration of 2-phospho-D-glycerate, which is comparable to the kinetic parameters of related enzymes. These results expand the understanding of the biophysical features of these enzymes, broadening the toolbox for metabolic engineering applications.