 |
PDBsum entry 3hte
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Motor protein
|
PDB id
|
|
|
|
3hte
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
Contents |
 |
|
|
|
|
|
|
|
|
|
|
|
317 a.a.
|
|
|
|
|
|
|
|
|
|
|
283 a.a.
|
|
|
|
|
|
|
|
|
|
|
301 a.a.
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Structures of asymmetric clpx hexamers reveal nucleotide-Dependent motions in a aaa+ protein-Unfolding machine.
|
|
|
Authors
|
|
S.E.Glynn,
A.Martin,
A.R.Nager,
T.A.Baker,
R.T.Sauer.
|
|
|
Ref.
|
|
Cell, 2009,
139,
744-756.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
ClpX is a AAA+ machine that uses the energy of ATP binding and hydrolysis to
unfold native proteins and translocate unfolded polypeptides into the ClpP
peptidase. The crystal structures presented here reveal striking asymmetry in
ring hexamers of nucleotide-free and nucleotide-bound ClpX. Asymmetry arises
from large changes in rotation between the large and small AAA+ domains of
individual subunits. These differences prevent nucleotide binding to two
subunits, generate a staggered arrangement of ClpX subunits and pore loops
around the hexameric ring, and provide a mechanism for coupling conformational
changes caused by ATP binding or hydrolysis in one subunit to flexing motions of
the entire ring. Our structures explain numerous solution studies of ClpX
function, predict mechanisms for pore elasticity during translocation of
irregular polypeptides, and suggest how repetitive conformational changes might
be coupled to mechanical work during the ATPase cycle of ClpX and related
molecular machines.
|
|
|
|
|
|
|
