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PDBsum entry 3bzc
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RNA binding protein
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PDB id
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3bzc
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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 and RNA binding of the tex protein from pseudomonas aeruginosa.
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Authors
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S.J.Johnson,
D.Close,
H.Robinson,
I.Vallet-Gely,
S.L.Dove,
C.P.Hill.
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Ref.
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J Mol Biol, 2008,
377,
1460-1473.
[DOI no: ]
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PubMed id
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Abstract
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Tex is a highly conserved bacterial protein that likely functions in a variety
of transcriptional processes. Here, we describe two crystal structures of the
86-kDa Tex protein from Pseudomonas aeruginosa at 2.3 and 2.5 A resolution,
respectively. These structures reveal a relatively flat and elongated protein,
with several potential nucleic acid binding motifs clustered at one end,
including an S1 domain near the C-terminus that displays considerable structural
flexibility. Tex binds nucleic acids, with a preference for single-stranded RNA,
and the Tex S1 domain is required for this binding activity. Point mutants
further demonstrate that the primary nucleic acid binding site corresponds to a
surface of the S1 domain. Sequence alignment and modeling indicate that the
eukaryotic Spt6 transcription factor adopts a similar core structure. Structural
analysis further suggests that the RNA polymerase and nucleosome interacting
regions of Spt6 flank opposite sides of the Tex-like scaffold. Therefore, the
Tex structure may represent a conserved scaffold that binds single-stranded RNA
to regulate transcription in both eukaryotic and prokaryotic organisms.
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Figure 2.
Fig. 2. Tex domain arrangement. (a and b) Orthogonal views of
ribbon diagram of the Tex structure. Structural motifs
identified from primary sequence and structural analyses are
colored. Blue, HtH motif. Red, YqgF homologous domain. Yellow,
tandem HhH motif. Green, S1 domain. (c) Tex domain structure,
colored as in (a) and (b). The segment boxed with broken lines,
comprising residues 1–730, indicates the region of Tex
sequence observed in the crystal structure.
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Figure 9.
Fig. 9. Model for Spt6 structure. (a) Comparison of Tex (top)
and Spt6 (bottom) domain structures. (b) The Tex structure is
used to model the central portion of the Spt6 structure (surface
representation). A proposed nucleosome-binding domain (magenta,
inset) is modeled based on structural alignment with the
C-terminal portion of the ISWI nucleosome interacting domain
(PDB accession code: 1OFC). An SH2-like domain (orange, PDB
accession code: 1PIC) is modeled at the C-terminal end of the S1
domain.
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The above figures are
reprinted
from an Open Access publication published by Elsevier:
J Mol Biol
(2008,
377,
1460-1473)
copyright 2008.
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