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PDBsum entry 2dfy
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Transcription
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PDB id
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2dfy
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References listed in PDB file
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Key reference
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Title
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Stabilization of a binary protein complex by intein-Mediated cyclization.
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Authors
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C.M.Jeffries,
S.C.Graham,
P.H.Stokes,
C.A.Collyer,
J.M.Guss,
J.M.Matthews.
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Ref.
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Protein Sci, 2006,
15,
2612-2618.
[DOI no: ]
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PubMed id
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Abstract
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The study of protein-protein interactions can be hampered by the instability of
one or more of the protein complex components. In this study, we showed that
intein-mediated cyclization can be used to engineer an artificial intramolecular
cyclic protein complex between two interacting proteins: the largely unstable
LIM-only protein 4 (LMO4) and an unstructured domain of LIM domain binding
protein 1 (ldb1). The X-ray structure of the cyclic complex is identical to
noncyclized versions of the complex. Chemical and thermal denaturation assays
using intrinsic tryptophan fluorescence and dynamic light scattering were used
to compare the relative stabilities of the cyclized complex, the intermolecular
(or free) complex, and two linear versions of the intramolecular complex (in
which the interacting domains of LMO4 and ldb1 were fused, via a flexible
linker, in either orientation). In terms of resistance to denaturation, the
cyclic complex is the most stable variant and the intermolecular complex is the
least stable; however, the two linear intramolecular variants show significant
differences in stability. These differences appear to be related to the relative
contact order (the average distance in sequence between residues that make
contacts within a structure) of key binding residues at the interface of the two
proteins. Thus, the restriction of the more stable component of a complex may
enhance stability to a greater extent than restraining less stable components.
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Figure 1.
Figure 1. Proposed intein-mediated in vivo protein cyclization mechanism. A target gene is cloned between the C- and N-terminal
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Figure 5.
Figure 5. cz-FLINC4 and FLINC4 are essentially identical. Structural alignment of cz-FLINC4 chain X (blue) and FLINC4 (green):
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The above figures are
reprinted
by permission from the Protein Society:
Protein Sci
(2006,
15,
2612-2618)
copyright 2006.
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