Backbone 1H, 13C, 15N NMR assignments of the unliganded and substrate ternary complex forms of mevalonate diphosphate decarboxylase from Streptococcus pneumoniae.

Mevalonate diphosphate decarboxylase (MDD) catalyzes the ATP-dependent decarboxylation of diphosphomevalonate (DPM) to produce isopentenyl diphosphate (IPP), the molecular "building block" for more than 25,000 distinct isoprenoids, including cholesterol, steroid hormones and terpenoids. Here, we present the first backbone assignment of Streptococcus pneumoniae MDD in the unliganded state and in a ternary complex with DPM and AMPPCP--a nucleotide analogue unable to transfer the γ-phosphoryl group. The secondary chemical shifts for the unliganded form are in good agreement with the crystal structure of Streptococcus pyogenes (~70% sequence identity). The addition of substrate and nucleotide to the enzyme results in chemical shift changes of cross peaks that correspond to residues in the binding pocket.