5m5m

From Proteopedia

(Difference between revisions)

Revision as of 19:03, 6 March 2020

Pseudo-atomic model of microtubule-bound S.pombe kinesin-5 motor domain in the AMPPNP state (based on cryo-electron microscopy experiment): the N-terminus adopts multiple conformations.

5m5m, resolution 9.30Å

Structural highlights

5m5m is a 3 chain structure with sequence from Bos taurus and Fission yeast. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Gene:	cut7, SPAC25G10.07c (Fission yeast)
Experimental data:	Check to display Experimental Data
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[TBA1D_BOVIN] Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain (By similarity). [CUT7_SCHPO] Could be a spindle pole body motor. On transition from G2 to M phase of the cell cycle, the spindle pole body duplicates; the daughter pole bodies seed microtubules which interdigitate to form a short spindle that elongates to span the nucleus at metaphase. Mutations at cut7 block spindle formation. [TBB2B_BOVIN] Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain (By similarity).

Publication Abstract from PubMed

Cut7, the sole kinesin-5 in Schizosaccharomyces pombe, is essential for mitosis. Like other yeast kinesin-5 motors, Cut7 can reverse its stepping direction, by mechanisms that are currently unclear. Here we show that for full-length Cut7, the key determinant of stepping direction is the degree of motor crowding on the microtubule lattice, with greater crowding converting the motor from minus end-directed to plus end-directed stepping. To explain how high Cut7 occupancy causes this reversal, we postulate a simple proximity sensing mechanism that operates via steric blocking. We propose that the minus end-directed stepping action of Cut7 is selectively inhibited by collisions with neighbors under crowded conditions, whereas its plus end-directed action, being less space-hungry, is not. In support of this idea, we show that the direction of Cut7-driven microtubule sliding can be reversed by crowding it with non-Cut7 proteins. Thus, crowding by either dynein microtubule binding domain or Klp2, a kinesin-14, converts Cut7 from net minus end-directed to net plus end-directed stepping. Biochemical assays confirm that the Cut7 N terminus increases Cut7 occupancy by binding directly to microtubules. Direct observation by cryoEM reveals that this occupancy-enhancing N-terminal domain is partially ordered. Overall, our data point to a steric blocking mechanism for directional reversal through which collisions of Cut7 motor domains with their neighbors inhibit their minus end-directed stepping action, but not their plus end-directed stepping action. Our model can potentially reconcile a number of previous, apparently conflicting, observations and proposals for the reversal mechanism of yeast kinesins-5.

Schizosaccharomyces pombe kinesin-5 switches direction using a steric blocking mechanism.,Britto M, Goulet A, Rizvi S, von Loeffelholz O, Moores CA, Cross RA Proc Natl Acad Sci U S A. 2016 Nov 22;113(47):E7483-E7489. Epub 2016 Nov 9. PMID:27834216^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Britto M, Goulet A, Rizvi S, von Loeffelholz O, Moores CA, Cross RA. Schizosaccharomyces pombe kinesin-5 switches direction using a steric blocking mechanism. Proc Natl Acad Sci U S A. 2016 Nov 22;113(47):E7483-E7489. Epub 2016 Nov 9. PMID:27834216 doi:http://dx.doi.org/10.1073/pnas.1611581113

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 See Also
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/5m5m"

@@ Line 1: / Line 1: @@
 ==Pseudo-atomic model of microtubule-bound S.pombe kinesin-5 motor domain in the AMPPNP state (based on cryo-electron microscopy experiment): the N-terminus adopts multiple conformations.==
-<StructureSection load='5m5m' size='340' side='right' caption='[[5m5m]], [[Resolution|resolution]] 9.30&Aring;' scene=''>
+<SX load='5m5m' size='340' side='right' viewer='molstar' caption='[[5m5m]], [[Resolution|resolution]] 9.30&Aring;' scene=''>
 == Structural highlights ==
 <table><tr><td colspan='2'>[[5m5m]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] and [http://en.wikipedia.org/wiki/Fission_yeast Fission yeast]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5M5M OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5M5M FirstGlance]. <br>
@@ Line 19: / Line 19: @@
 </div>
 <div class="pdbe-citations 5m5m" style="background-color:#fffaf0;"></div>
+==See Also==
+*[[Kinesin 3D Structures|Kinesin 3D Structures]]
+*[[Tubulin|Tubulin]]
 == References ==
 <references/>
 __TOC__
-</StructureSection>
+</SX>
 [[Category: Bos taurus]]
 [[Category: Fission yeast]]
+[[Category: Large Structures]]
 [[Category: Cross, R A]]
 [[Category: Goulet, A]]

5m5m

From Proteopedia

Revision as of 19:03, 6 March 2020

Pseudo-atomic model of microtubule-bound S.pombe kinesin-5 motor domain in the AMPPNP state (based on cryo-electron microscopy experiment): the N-terminus adopts multiple conformations.

Structural highlights

Function

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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