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PDBsum entry 1ry6
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Transport protein
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PDB id
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1ry6
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Structure of a kinesin microtubule depolymerization machine.
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Authors
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K.Shipley,
M.Hekmat-Nejad,
J.Turner,
C.Moores,
R.Anderson,
R.Milligan,
R.Sakowicz,
R.Fletterick.
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Ref.
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EMBO J, 2004,
23,
1422-1432.
[DOI no: ]
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PubMed id
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Abstract
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With their ability to depolymerize microtubules (MTs), KinI kinesins are the
rogue members of the kinesin family. Here we present the 1.6 A crystal structure
of a KinI motor core from Plasmodium falciparum, which is sufficient for
depolymerization in vitro. Unlike all published kinesin structures to date,
nucleotide is not present, and there are noticeable differences in loop regions
L6 and L10 (the plus-end tip), L2 and L8 and in switch II (L11 and helix4);
otherwise, the pKinI structure is very similar to previous kinesin structures.
KinI-conserved amino acids were mutated to alanine, and studied for their
effects on depolymerization and ATP hydrolysis. Notably, mutation of three
residues in L2 appears to primarily affect depolymerization, rather than general
MT binding or ATP hydrolysis. The results of this study confirm the suspected
importance of loop 2 for KinI function, and provide evidence that KinI is
specialized to hydrolyze ATP after initiating depolymerization.
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Figure 2.
Figure 2 Comparison of pKinI with the most structurally similar
gliding motor NCD. Common elements are shown in gray, differing
pKinI parts in red and differing NCD parts in blue. The sulfate
ion that marks the  -phosphate
of ADP is shown in yellow. The largest differences are the
length of L2, the positioning of the 'tip' (L6 and L10), the
direction of L8 and the unusual stability of the switch II
region (L11-  4).
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Figure 5.
Figure 5 Location of pKinI amino-acid substitutions. Red spheres
mark the three residues and two-residue triplets (K40/V41/D42
and K268/E269/C270) that were mutated to alanine and assayed for
their effects on ATP hydrolysis and MT depolymerization.
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The above figures are
reprinted
from an Open Access publication published by Macmillan Publishers Ltd:
EMBO J
(2004,
23,
1422-1432)
copyright 2004.
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