Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.6.4.4 (
kinesin
)
5,033
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We have used site-directed spin-labeling and electron paramagnetic resonance spectroscopy to monitor a conformational change at the nucleotide site of
kinesin
. Cys-lite
kinesin
(K349 monomer) with the mutation S188C was spin labeled with
MSL
or MTSL. This residue is at the junction between the switch 1 region (which is a structure known to be sensitive to bound nucleotide in the G-proteins) and the alpha3-helix, adjacent to the nucleotide site. The spectra showed two or more components of mobility, which were independent of nucleotide in the absence of microtubules (MTs). The spectra of both labels showed a change of mobility upon binding to MTs. A more mobile spectral component became enhanced for all triphosphate analogs examined, AMPPNP, ADP.AlFx, or ADP.BeFx, in the presence of MTs, although the magnitude of the new component and the degree of mobility varied with nucleotide analog. The ADP state showed a much-reduced spectral change with a small shift to the more immobilized component in the presence of MTs. For
kinesin
.ADP.MT, a van't Hoff plot gave DeltaH degrees = -96 kJ/mol implying that the conformational change was extensive. We conclude there is a conformational change in the switch 1-alpha3-helix domain when
kinesin
binds to MTs.
...
PMID:EPR spectroscopy shows a microtubule-dependent conformational change in the kinesin switch 1 domain. 1271 48
