TY - JOUR
T1 - Menaquinone-specific prenyl reductase from the hyperthermophilic archaeon Archaeoglobus fulgidus
AU - Hemmi, Hisashi
AU - Takahashi, Yoshihiro
AU - Shibuya, Kyohei
AU - Nakayama, Toru
AU - Nishino, Tokuzo
PY - 2005/3
Y1 - 2005/3
N2 - Four genes that encode the homologues of plant geranylgeranyl reductase were isolated from a hyperthermophilic archaeon Archaeoglobus fulgidus, which produces menaquinone with a fully saturated heptaprenyl side chain, menaquinone-7(14H). The recombinant expression of one of the homologues in Escherichia coli led to a distinct change in the quinone profile of the host cells, although the homologue is the most distantly related to the geranylgeranyl reductase. The new compounds found in the profile had successively longer elution times than those of ordinary quinones from E. coli, i.e., menaquinone-8 and ubiquinone-8, in high-performance liquid chromatography on a reversed-phase column. Structural analyses of the new compounds by electron impact-mass spectrometry indicated that their molecular masses progressively increase relative to the ordinary quinones at a rate of 2 U but that they still contain quinone head structures, strongly suggesting that the compounds are quinones with partially saturated prenyl side chains. In vitro assays with dithionite as the reducing agent showed that the prenyl reductase is highly specific for menaquinone-7, rather than ubiquinone-8 and prenyl diphosphates. This novel enzyme noncovalently binds flavin adenine dinucleotide, similar to geranylgeranyl reductase, but was not able to utilize NAD(P)H as the electron donor, unlike the plant homologue.
AB - Four genes that encode the homologues of plant geranylgeranyl reductase were isolated from a hyperthermophilic archaeon Archaeoglobus fulgidus, which produces menaquinone with a fully saturated heptaprenyl side chain, menaquinone-7(14H). The recombinant expression of one of the homologues in Escherichia coli led to a distinct change in the quinone profile of the host cells, although the homologue is the most distantly related to the geranylgeranyl reductase. The new compounds found in the profile had successively longer elution times than those of ordinary quinones from E. coli, i.e., menaquinone-8 and ubiquinone-8, in high-performance liquid chromatography on a reversed-phase column. Structural analyses of the new compounds by electron impact-mass spectrometry indicated that their molecular masses progressively increase relative to the ordinary quinones at a rate of 2 U but that they still contain quinone head structures, strongly suggesting that the compounds are quinones with partially saturated prenyl side chains. In vitro assays with dithionite as the reducing agent showed that the prenyl reductase is highly specific for menaquinone-7, rather than ubiquinone-8 and prenyl diphosphates. This novel enzyme noncovalently binds flavin adenine dinucleotide, similar to geranylgeranyl reductase, but was not able to utilize NAD(P)H as the electron donor, unlike the plant homologue.
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U2 - 10.1128/JB.187.6.1937-1944.2005
DO - 10.1128/JB.187.6.1937-1944.2005
M3 - Article
C2 - 15743940
AN - SCOPUS:14644401708
VL - 187
SP - 1937
EP - 1944
JO - Journal of Bacteriology
JF - Journal of Bacteriology
SN - 0021-9193
IS - 6
ER -