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PDBsum entry 2g0y
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Unknown function
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PDB id
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2g0y
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References listed in PDB file
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Key reference
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Title
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Characterization of two potentially universal turn motifs that shape the repeated five-Residues fold--Crystal structure of a lumenal pentapeptide repeat protein from cyanothece 51142.
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Authors
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G.W.Buchko,
S.Ni,
H.Robinson,
E.A.Welsh,
H.B.Pakrasi,
M.A.Kennedy.
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Ref.
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Protein Sci, 2006,
15,
2579-2595.
[DOI no: ]
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PubMed id
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Abstract
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The genome of the diurnal cyanobacterium Cyanothece sp. PCC 51142 has recently
been sequenced and observed to contain 35 pentapeptide repeat proteins (PRPs).
These proteins, while present throughout the prokaryotic and eukaryotic
kingdoms, are most abundant in cyanobacteria. The sheer number of PRPs in
cyanobacteria coupled with their predicted location in every cellular
compartment argues for important, yet unknown, physiological and biochemical
functions. To gain biochemical insights, the crystal structure for Rfr32, a
167-residue PRP with an N-terminal 29-residue signal peptide, was determined at
2.1 A resolution. The structure is dominated by 21 tandem pentapeptide repeats
that fold into a right-handed quadrilateral beta-helix, or Rfr-fold, as observed
for the tandem pentapeptide repeats in the only other PRP structure, the
mycobacterial fluoroquinoline resistance protein MfpA from Mycobacterium
tuberculosis. Sitting on top of the Rfr-fold are two short, antiparallel
alpha-helices, bridged with a disulfide bond, that perhaps prevent edge-to-edge
aggregation at the C terminus. Analysis of the main-chain (Phi,Psi) dihedral
orientations for the pentapeptide repeats in Rfr32 and MfpA makes it possible to
recognize the structural details for the two distinct types of four-residue
turns adopted by the pentapeptide repeats in the Rfr-fold. These turns, labeled
type II and type IV beta-turns, may be universal motifs that shape the Rfr-fold
in all PRPs.
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Figure 10.
Figure 10. Predicted residue composition of the 35 PRPs in Cyanothece
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The above figure is
reprinted
by permission from the Protein Society:
Protein Sci
(2006,
15,
2579-2595)
copyright 2006.
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