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Formin steps and slips

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Formin caps the barbed ends of actin filaments, yet allows more monomers to be added... It has been proposed that a formin dimer works as if climbing stairs... The formin dimer initially contacts the terminal actin monomers but then releases its grip on the actin monomer second from the top, allowing it to bind a new actin monomer... When that new actin monomer is added, the free half of the formin dimer attaches to it... The other half of formin then releases its actin, and so on... The model made sense but did not explain how torsion was accommodated... But the cap might also turn the long way around (∼166°) in a screw-like mode if both halves of the formin dimer transiently release actin... The group modeled this theory using an elastic energy analysis... The authors propose that torsional stress builds up with stair stepping until it is energetically favorable for formin to slip into screw mode... They estimate that every 12 steps should be followed by one screw mode slip... Although the prediction still awaits experimental verification, the regulation of polymerization mode by stress might apply to more than just actin.

No MeSH data available.


A formin dimer (blue and green) takes several steps (left) and then changes to screw mode (right).
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uro1: A formin dimer (blue and green) takes several steps (left) and then changes to screw mode (right).


Formin steps and slips
A formin dimer (blue and green) takes several steps (left) and then changes to screw mode (right).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2254895&req=5

uro1: A formin dimer (blue and green) takes several steps (left) and then changes to screw mode (right).

View Article: PubMed Central

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Formin caps the barbed ends of actin filaments, yet allows more monomers to be added... It has been proposed that a formin dimer works as if climbing stairs... The formin dimer initially contacts the terminal actin monomers but then releases its grip on the actin monomer second from the top, allowing it to bind a new actin monomer... When that new actin monomer is added, the free half of the formin dimer attaches to it... The other half of formin then releases its actin, and so on... The model made sense but did not explain how torsion was accommodated... But the cap might also turn the long way around (∼166°) in a screw-like mode if both halves of the formin dimer transiently release actin... The group modeled this theory using an elastic energy analysis... The authors propose that torsional stress builds up with stair stepping until it is energetically favorable for formin to slip into screw mode... They estimate that every 12 steps should be followed by one screw mode slip... Although the prediction still awaits experimental verification, the regulation of polymerization mode by stress might apply to more than just actin.

No MeSH data available.