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PDBsum entry 1fcv
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Crystal structure of hyaluronidase, A major allergen of bee venom.
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Authors
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Z.Marković-Housley,
G.Miglierini,
L.Soldatova,
P.J.Rizkallah,
U.Müller,
T.Schirmer.
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Ref.
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Structure, 2000,
8,
1025-1035.
[DOI no: ]
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PubMed id
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Abstract
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BACKGROUND: Hyaluronic acid (HA) is the most abundant glycosaminoglycan of
vertebrate extracellular spaces and is specifically degraded by a beta-1,4
glycosidase. Bee venom hyaluronidase (Hya) shares 30% sequence identity with
human hyaluronidases, which are involved in fertilization and the turnover of
HA. On the basis of sequence similarity, mammalian enzymes and Hya are assigned
to glycosidase family 56 for which no structure has been reported yet. RESULTS:
The crystal structure of recombinant (Baculovirus) Hya was determined at 1.6 A
resolution. The overall topology resembles a classical (beta/alpha)(8) TIM
barrel except that the barrel is composed of only seven strands. A long
substrate binding groove extends across the C-terminal end of the barrel.
Cocrystallization with a substrate analog revealed the presence of a HA tetramer
bound to subsites -4 to -1 and distortion of the -1 sugar. CONCLUSIONS: The
structure of the complex strongly suggest an acid-base catalytic mechanism, in
which Glu113 acts as the proton donor and the N-acetyl group of the substrate is
the nucleophile. The location of the catalytic residues shows striking
similarity to bacterial chitinase which also operates via a substrate-assisted
mechanism.
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Figure 2.
Figure 2. Representative Section of the Final Electron
Density MapClose-up stereo view of the segment 111-116,
including the proton donor Glu113, overlaid onto the final
SigmaA-weighted 2F[o]-F[c] map [71] contoured at 1s. Figure 2,
Figure 3, Figure 5, Figure 6 and Figure 7 were produced using
the program DINO (A. Philippsen,
http://www.biozentrum.unibas.ch/~xray/dino)
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The above figure is
reprinted
by permission from Cell Press:
Structure
(2000,
8,
1025-1035)
copyright 2000.
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