 |
PDBsum entry 4eiw
|
|
|
|
References listed in PDB file
|
 |
|
Key reference
|
|
|
Title
|
|
Structure of the whole cytosolic region of ATP-Dependent protease ftsh.
|
|
|
Authors
|
|
R.Suno,
H.Niwa,
D.Tsuchiya,
X.Zhang,
M.Yoshida,
K.Morikawa.
|
|
|
Ref.
|
|
Mol Cell, 2006,
22,
575-585.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
An ATP-dependent protease, FtsH, digests misassembled membrane proteins in order
to maintain membrane integrity and digests short-lived soluble proteins in order
to control their cellular regulation. This enzyme has an N-terminal
transmembrane segment and a C-terminal cytosolic region consisting of an AAA+
ATPase domain and a protease domain. Here we present two crystal structures: the
protease domain and the whole cytosolic region. The cytosolic region fully
retains an ATP-dependent protease activity and adopts a three-fold-symmetric
hexameric structure. The protease domains displayed a six-fold symmetry, while
the AAA+ domains, each containing ADP, alternate two orientations relative to
the protease domain, making "open" and "closed" interdomain
contacts. Apparently, ATPase is active only in the closed form, and protease
operates in the open form. The protease catalytic sites are accessible only
through a tunnel following from the AAA+ domain of the adjacent subunit, raising
a possibility of translocation of polypeptide substrate to the protease sites
through this tunnel.
|
|
|
|
|
|
|
|
Figure 4.
Figure 4. Catalytic Environments in sFtsH
|
|
Figure 6.
Figure 6. The ATPase Cycle and Putative Polypeptide
Translocation Pathway
|
|
|
|
|
|
The above figures are
reprinted
by permission from Cell Press:
Mol Cell
(2006,
22,
575-585)
copyright 2006.
|
|
|
Secondary reference #1
|
|
|
Title
|
|
Hexameric ring structure of the atpase domain of the membrane-Integrated metalloprotease ftsh from thermus thermophilus hb8.
|
|
|
Authors
|
|
H.Niwa,
D.Tsuchiya,
H.Makyio,
M.Yoshida,
K.Morikawa.
|
|
|
Ref.
|
|
Structure, 2002,
10,
1415-1423.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
|
|
|
Figure 3.
Figure 3. Hexameric Ring Model of the FtsH ATPase Domain(A)
The figures are viewed from the transmembrane side (left) and
the protease domain side (right). From the extra segment
position of the FtsH-F2 crystal structure, we found that the
transmembrane helices are located on the N-terminal side of the
hexagonal plate. The model possesses an outer diameter of
approximately 120 Å, with a central pore of 13 Å in diameter.
Note the gap between subunits, which becomes narrow in
comparison with that in the crystal packing arrangement, as
shown in Figure 1D. The rotation angle between subdomains in the
model differs by 34° from that in the crystal. Although every
subunit is represented with the same conformation in this model,
the mode of the ATPase cycle, either sequential or synchronized,
cannot be clarified.(B) Representation of the arginine finger in
the model viewed from the transmembrane side. Arg313 is located
at a position capable of interacting with the g-phosphate of
AMP-PNP bound to a neighboring subunit. The SRH motif,
highlighted in pink, is located on the contact surface between
subunits. The a7 helix and the following loop in front of Arg313
are eliminated.(C) SRH motif in the model, viewed from the
protease domain side. The motif from the AMP-PNP form is
superimposed onto that from the ADP form. The Ca atom of Asn302
is colored red.(D) Mapping of the putative substrate binding
regions (brown). Note that the MFVG sequence (green) faces the
central pore. A closed line indicates a monomer structure,
corresponding to the highlighted one in (A).(E) Electrostatic
potential surfaces of the model, calculated by the program GRASP
[52]. Red and blue represent regions of negative and positive
potential, respectively.
|
|
|
|
|
|
The above figure is
reproduced from the cited reference
with permission from Cell Press
|
|
|
|
|
|
|
