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PDBsum entry 1avx
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Complex (proteinase/inhibitor)
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PDB id
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1avx
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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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Kunitz-Type soybean trypsin inhibitor revisited: refined structure of its complex with porcine trypsin reveals an insight into the interaction between a homologous inhibitor from erythrina caffra and tissue-Type plasminogen activator.
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Authors
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H.K.Song,
S.W.Suh.
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Ref.
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J Mol Biol, 1998,
275,
347-363.
[DOI no: ]
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PubMed id
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Abstract
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The Kunitz-type trypsin inhibitor from soybean (STI) consists of 181 amino acid
residues with two disulfide bridges. Its crystal structures have been determined
in complex with porcine pancreatic trypsin in two crystal forms (an orthorhombic
form at 1.75 A resolution and a tetragonal form at 1.9 A) and in the free state
at 2.3 A resolution. They have been refined to crystallographic R-values of
18.9%, 21.6% and 19.8%, respectively. The three models of STI reported here
represent a significant improvement over the partial inhibitor structure in the
complex, which was previously determined at a nominal resolution of 2.6 A by the
multiple isomorphous replacement method. This study provides the first
high-resolution picture of the complex between a Kunitz-type proteinase
inhibitor with its cognate proteinase. Many of the external loops of STI show
high B-factors, both in the free and the complexed states, except the reactive
site loop whose B-factors are dramatically reduced upon complexation. The
reactive site loop of STI adopts a canonical conformation similar to those in
other substrate-like inhibitors. The P1 carbonyl group displays no out-of-plane
displacement and thus retains a nominal trigonal planar geometry. Modeling
studies on the complex between a homologous Kunitz-type trypsin inhibitor DE-3
from Erythrina caffra and the human tissue-type plasminogen activator reveal a
new insight into the specific interactions which could play a crucial role in
their binding.
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Figure 5.
Figure 5. Stereo diagram showing the interactions between
the bound water molecule (Wat34) and three β-strands (Aβ3,
Bβ3 and Cβ3). The distances between the water and oxygen atoms
of the inhibitor are given, with a distance too long for a
hydrogen bond in parenthesis.
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Figure 13.
Figure 13. A comparison of molecular surfaces. Positively
charged regions are blue and negatively charged regions red. The
P1 residue, S1 pocket and some basic and acidic patches are
labeled. This figure was generated using GRASP (Nicholls, 1992).
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The above figures are
reprinted
by permission from Elsevier:
J Mol Biol
(1998,
275,
347-363)
copyright 1998.
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Secondary reference #1
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Title
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Author
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H.K.Song.
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Ref.
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crystal structure analyses ...
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Secondary reference #2
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Title
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Crystallization of kunitz-Type soybean trypsin inhibitor
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Authors
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J.K.Lee,
H.K.Song,
K.Y.Hwang,
K.K.Kim,
S.W.Suh.
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Ref.
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mol cells, 1993,
3,
335.
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Secondary reference #3
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Title
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Author
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J.K.Lee.
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Ref.
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crystallization and ...
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