Determination of kinetics and the crystal structure of a novel type 2 isopentenyl diphosphate: dimethylallyl diphosphate isomerase from Streptococcus pneumoniae.
Abstract
peer reviewedIsopentenyl diphosphate isomerase (IDI) is a key enzyme in the isoprenoid biosynthetic pathway and is required for all organisms that synthesize isoprenoid metabolites from mevalonate. Type 1 IDI (IDI-1) is a metalloprotein that is found in eukaryotes, whereas the type 2 isoform (IDI-2) is a flavoenzyme found in bacteria that is completely absent from human. IDI-2 from the pathogenic bacterium Streptococcus pneumoniae was recombinantly expressed in Escherichia coli. Steady-state kinetic studies of the enzyme indicated that FMNH2 (KM =0.3 muM) bound before isopentenyl diphosphate (KM =40 muM) in an ordered binding mechanism. An X-ray crystal structure at 1.4 A resolution was obtained for the holoenzyme in the closed conformation with a reduced flavin cofactor and two sulfate ions in the active site. These results helped to further approach the enzymatic mechanism of IDI-2 and, thus, open new possibilities for the rational design of antibacterial compounds against sequence-similar and structure-related pathogens such as Enterococcus faecalis or Staphylococcus aureus- journal article
- http://purl.org/coar/resource_type/c_6501
- info:eu-repo/semantics/article
- peer reviewed
- X-ray structures
- bisubstrates
- flavoproteins
- isoprenoids
- steady-state kinetics
- circular dichroism
- Life sciences
- Biochemistry, biophysics & molecular biology
- Sciences du vivant
- Biochimie, biophysique & biologie moléculaire