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PDBsum entry 2fge
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Hydrolase, plant protein
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PDB id
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2fge
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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 closed structure of presequence protease prep forms a unique 10,000 angstroms3 chamber for proteolysis.
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Authors
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K.A.Johnson,
S.Bhushan,
A.Ståhl,
B.M.Hallberg,
A.Frohn,
E.Glaser,
T.Eneqvist.
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Ref.
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EMBO J, 2006,
25,
1977-1986.
[DOI no: ]
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PubMed id
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Abstract
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Presequence protease PreP is a novel protease that degrades targeting peptides
as well as other unstructured peptides in both mitochondria and chloroplasts.
The first structure of PreP from Arabidopsis thaliana refined at 2.1 Angstroms
resolution shows how the 995-residue polypeptide forms a unique proteolytic
chamber of more than 10,000 Angstroms(3) in which the active site resides.
Although there is no visible opening to the chamber, a peptide is bound to the
active site. The closed conformation places previously unidentified residues
from the C-terminal domain at the active site, separated by almost 800 residues
in sequence to active site residues located in the N-terminal domain. Based on
the structure, a novel mechanism for proteolysis is proposed involving
hinge-bending motions that cause the protease to open and close in response to
substrate binding. In support of this model, cysteine double mutants designed to
keep the chamber covalently locked show no activity under oxidizing conditions.
The manner in which substrates are processed inside the chamber is reminiscent
of the proteasome; therefore, we refer to this protein as a peptidasome.
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Figure 5.
Figure 5 Proposed mechanism for the PreP peptidasome substrate
binding and release.
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Figure 6.
Figure 6 AtPreP1 is inactive if locked in a closed conformation.
(A) Schematic representation of the AtPreP1 cysteine double
mutants K171C-G852C (C1), K179C-Q810C (C2), E345C-S682C (C3) and
A331C-N615C (C4) under reducing and oxidizing conditions.
Proteolytic activity of native (wt) AtPreP1 and the cysteine
double mutants measured as the degradation of N[5.7]pF[1]  (2–54)
under reducing (B) and oxidizing conditions (C) and degradation
of the P1 peptide under reducing (D) and oxidizing conditions
(E).
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The above figures are
reprinted
by permission from Macmillan Publishers Ltd:
EMBO J
(2006,
25,
1977-1986)
copyright 2006.
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Secondary reference #1
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Title
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Characterization of a novel zinc metalloprotease involved in degrading targeting peptides in mitochondria and chloroplasts.
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Authors
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P.Moberg,
A.Ståhl,
S.Bhushan,
S.J.Wright,
A.Eriksson,
B.D.Bruce,
E.Glaser.
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Ref.
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Plant J, 2003,
36,
616-628.
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PubMed id
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