Linked Life Data

2719934

Source:http://linkedlifedata.com/resource/pubmed/id/2719934

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1989-6-27
pubmed:abstractText
Beryllium fluoride (BeF3-) has previously been shown to bind tightly to microtubules as a structural analogue of Pi and to mimic the GDP-Pi transient state in tubulin polymerization [Carlier, M.-F., Didry, D., Melki, R., Chabre, M., & Pantaloni, D. (1988) Biochemistry 27, 3555-3559]. The interaction of BeF3- with tubulin is analyzed here in greater detail. BeF3- binds to and dissociates from microtubule GDP subunits at very slow rates (k+ congruent to 100 M-1 s-1; k- congruent to 6 x 10(-4) s-1), suggesting that a slow conformation change of tubulin, linked to the stabilization of the microtubule structure, follows BeF3- binding. The possibility is evoked that BeF3- acts as a transition-state analogue in the GTPase reaction of tubulin. BeF3- does not bind to dimeric nor to oligomeric GDP-tubulin with high affinity. Substoichiometric binding of BeF3- to microtubules provides extensive stabilization of the structure. An original mechanistic model that accounts for the data is proposed. The kinetic parameters for microtubule elongation in the presence of GTP- and GDP-tubulin with and without BeF3- have been determined. Data support the following views: (i) Microtubules at steady state and in a regime of slow growth in the presence of GTP are stabilized by a cap of GDP-Pi subunits functionally similar to GDP-BeF3 subunits. (ii) In the presence of BeF3-, microtubules elongate from GDP-tubulin within the following sequence of reactions: initial nonproductive binding of GDP-tubulin to microtubule ends is followed by the binding of BeF3- and the associated conformation change allowing sustained elongation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1783-91
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Mechanism of GTP hydrolysis in tubulin polymerization: characterization of the kinetic intermediate microtubule-GDP-Pi using phosphate analogues.
pubmed:affiliation
Laboratoire d'Enzymologie du CNRS, Gif-sur-Yvette, France.
pubmed:publicationType
Journal Article