2d36: Difference between revisions

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The Crystal Structure of Flavin Reductase HpaC

OverviewOverview

4-Hydroxyphenylacetate (4-HPA) is oxidized as an energy source by two component enzymes, the large component (HpaB) and the small component (HpaC). HpaB is a 4-HPA monooxygenase that utilizes FADH(2) supplied by a flavin reductase HpaC. We determined the crystal structure of HpaC (ST0723) from the aerobic thermoacidophilic crenarchaeon Sulfolobus tokodaii strain 7 in its three states [NAD(P)(+)-free, NAD(+)-bound, and NADP(+)-bound]. HpaC exists as a homodimer, and each monomer was found to contain an FMN. HpaC preferred FMN to FAD because there was not enough space to accommodate the AMP moiety of FAD in its flavin-binding site. The most striking difference between the NAD(P)(+)-free and the NAD(+)/NADP(+)-bound structures was observed in the N-terminal helix. The N-terminal helices in the NAD(+)/NADP(+)-bound structures rotated ca. 20 degrees relative to the NAD(P)(+)-free structure. The bound NAD(+) has a compact folded conformation with nearly parallel stacking rings of nicotinamide and adenine. The nicotinamide of NAD(+) stacked the isoalloxazine ring of FMN so that NADH could directly transfer hydride. The bound NADP(+) also had a compact conformation but was bound in a reverse direction, which was not suitable for hydride transfer.

About this StructureAbout this Structure

2D36 is a Single protein structure of sequence from Sulfolobus tokodaii str. 7 with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

Crystal structures of the short-chain flavin reductase HpaC from Sulfolobus tokodaii strain 7 in its three states: NAD(P)(+)(-)free, NAD(+)(-)bound, and NADP(+)(-)bound., Okai M, Kudo N, Lee WC, Kamo M, Nagata K, Tanokura M, Biochemistry. 2006 Apr 25;45(16):5103-10. PMID:16618099

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 ==Overview==
--Hydroxyphenylacetate (4-HPA) is oxidized as an energy source by two, component enzymes, the large component (HpaB) and the small component, (HpaC). HpaB is a 4-HPA monooxygenase that utilizes FADH(2) supplied by a, flavin reductase HpaC. We determined the crystal structure of HpaC, (ST0723) from the aerobic thermoacidophilic crenarchaeon Sulfolobus, tokodaii strain 7 in its three states [NAD(P)(+)-free, NAD(+)-bound, and, NADP(+)-bound]. HpaC exists as a homodimer, and each monomer was found to, contain an FMN. HpaC preferred FMN to FAD because there was not enough, space to accommodate the AMP moiety of FAD in its flavin-binding site. The, most striking difference between the NAD(P)(+)-free and the, NAD(+)/NADP(+)-bound structures was observed in the N-terminal helix. The, N-terminal helices in the NAD(+)/NADP(+)-bound structures rotated ca. 20, degrees relative to the NAD(P)(+)-free structure. The bound NAD(+) has a, compact folded conformation with nearly parallel stacking rings of, nicotinamide and adenine. The nicotinamide of NAD(+) stacked the, isoalloxazine ring of FMN so that NADH could directly transfer hydride., The bound NADP(+) also had a compact conformation but was bound in a, reverse direction, which was not suitable for hydride transfer.
+-Hydroxyphenylacetate (4-HPA) is oxidized as an energy source by two component enzymes, the large component (HpaB) and the small component (HpaC). HpaB is a 4-HPA monooxygenase that utilizes FADH(2) supplied by a flavin reductase HpaC. We determined the crystal structure of HpaC (ST0723) from the aerobic thermoacidophilic crenarchaeon Sulfolobus tokodaii strain 7 in its three states [NAD(P)(+)-free, NAD(+)-bound, and NADP(+)-bound]. HpaC exists as a homodimer, and each monomer was found to contain an FMN. HpaC preferred FMN to FAD because there was not enough space to accommodate the AMP moiety of FAD in its flavin-binding site. The most striking difference between the NAD(P)(+)-free and the NAD(+)/NADP(+)-bound structures was observed in the N-terminal helix. The N-terminal helices in the NAD(+)/NADP(+)-bound structures rotated ca. 20 degrees relative to the NAD(P)(+)-free structure. The bound NAD(+) has a compact folded conformation with nearly parallel stacking rings of nicotinamide and adenine. The nicotinamide of NAD(+) stacked the isoalloxazine ring of FMN so that NADH could directly transfer hydride. The bound NADP(+) also had a compact conformation but was bound in a reverse direction, which was not suitable for hydride transfer.
 ==About this Structure==
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 [[Category: Kamo, M.]]
 [[Category: Kudo, N.]]
-[[Category: Lee, W.C.]]
+[[Category: Lee, W C.]]
 [[Category: Nagata, K.]]
 [[Category: Okai, M.]]
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 [[Category: flavin reductase]]
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