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PDBsum entry 1cbk
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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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The structure and function of the 6-Hydroxymethyl-7,8-Dihydropterin pyrophosphokinase from haemophilus influenzae.
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Authors
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M.Hennig,
G.E.Dale,
A.D'Arcy,
F.Danel,
S.Fischer,
C.P.Gray,
S.Jolidon,
F.Müller,
M.G.Page,
P.Pattison,
C.Oefner.
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Ref.
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J Mol Biol, 1999,
287,
211-219.
[DOI no: ]
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PubMed id
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Abstract
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The gene encoding the 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase of
Haemophilus influenzae has been cloned and expressed in Escherichia coli. A
complex of the purified protein with a substrate analog has been crystallized
and its structure solved by multiple anomalous dispersion using phase
information obtained from a single crystal of selenomethione-labeled protein.
The enzyme folds into a four-stranded antiparallel beta-sheet flanked on one
side by two alpha-helices and on the other by three consecutive alpha-helices,
giving a novel beta1alpha1beta2beta3alpha2beta4alpha3alpha4alpha5 polypeptide
topology. The three-dimensional structure of a binary complex has been refined
at 2.1 A resolution. The location of the substrate analog and a sulfate ion
gives important insight into the molecular mechanism of the enzyme.
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Figure 5.
Figure 5. Structure of the HPPK monomer. (a) In the overall
view β-strands are presented as arrows and α-helices are shown
as ribbons. The inhibitor in the active site is represented by
the ball-and-stick model in green. (b) The molecular surface of
the enzyme in the absence of compound [II] depicts the position
of the conserved charged amino acid residues in the proximity of
the pterin binding site. The surface is colored red and blue for
negative and positive char respectively. The Figure was produced
using the programs MOLSCRIPT [Kraulis 1991] and RASTER3D [Merrit
and Bacon 1997]. The surface was generated and displayed with
the program GRASP [Nicholls and Honig 1992].
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Figure 6.
Figure 6. Refined structure of the active site region of HPPK
superimposed with the MAD electron density at 2.6 Å
resolution contoured at (a) 1.5σ and (b) the final 2 F[o] −
F[c] map at 2.1 Å contoured at 1σ. The protein, inhibitor
and sulfate ion is represented in red, green or blue,
respectively. Water molecules are shown by small spheres. The
Figure was produces with the program MOLOC [Gerber 1992].
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The above figures are
reprinted
by permission from Elsevier:
J Mol Biol
(1999,
287,
211-219)
copyright 1999.
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