Possible direct involvement of the active-site [4Fe-4S] cluster of the GcpE enzyme from Thermus thermophilus in the conversion of MEcPP.
The GcpE enzyme converts 2-C-methyl-D-erythritol-2,4-cyclodiphosphate (MEcPP) into (E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP) in the penultimate step of the DOXP pathway for isoprene biosynthesis. Purification of the enzyme under exclusion of air leads to a preparation that contains solely [4Fe-4S] clusters. Kinetic studies showed that in the presence of the artificial reductant dithionite and MEcPP a new transient iron-sulfur-based signal is detected in electron paramagnetic resonance (EPR) spectroscopy. Similarity of this EPR signal to that detected in ferredoxin:thioredoxin reductase indicates that during the reaction an intermediate is directly bound to the active-site cluster.
Adedeji
Dolapo
D
Department of Chemistry and Biochemistry, Auburn University, 179 Chemistry Building, Auburn, AL 36849, USA.
Hernandez
Heather
H
Wiesner
Jochen
J
Köhler
Uwe
U
Jomaa
Hassan
H
Duin
Evert C
EC
D001665:Binding Sites; D004578:Electron Spin Resonance Spectroscopy; D004798:Enzymes / Q000737:chemistry* / Q000302:isolation & purification; D004896:Erythritol / Q000031:analogs & derivatives* / Q000378:metabolism; D007501:Iron / Q000032:analysis; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000302:isolation & purification; D010755:Organophosphates / Q000378:metabolism; D010428:Pentosephosphates / Q000378:metabolism; D013455:Sulfur / Q000032:analysis; D016963:Thermus thermophilus / Q000201:enzymology*
C109460:1-deoxylulose 5-phosphate; C467061:4-hydroxy-3-methyl-2-butenyl diphosphate; D004798:Enzymes; D007506:Iron-Sulfur Proteins; D010755:Organophosphates; D010428:Pentosephosphates; C421242:hydroxymethylbutenyl 4-diphosphate synthase; C443879:methyl-D-erythritol 2,4-cyclodiphosphate; D013455:Sulfur; D007501:Iron; D004896:Erythritol