Linked Life Data

10395830

Source:http://linkedlifedata.com/resource/pubmed/id/10395830

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-8-12
pubmed:abstractText
Motifs N2 and N3, also referred to as switch-1 and switch-2, form part of the active site of molecular motors such as myosins and kinesins. In the case of myosin, N3 is thought to act as a gamma-phosphate sensor and moves almost 6 A relative to N2 during the catalysed turnover of ATP, opening and closing the active site surrounding the gamma-phosphate. The closed form seems to be necessary for hydrolysis and is stabilised by the formation of a salt-bridge between an arginine residue in N2 and a glutamate residue in N3. We examined the role of this salt-bridge in Dictyostelium discoideum myosin. Myosin motor domains with mutations E459R or R238E, that block salt-bridge formation, show defects in nucleotide-binding, reduced rates of ATP hydrolysis and a tenfold reduction in actin affinity. Inversion of the salt-bridge in double-mutant M765-IS eliminates most of the defects observed for the single mutants. With the exception of a 2,500-fold higher KMvalue for ATP, the double-mutant displayed enzymatic and functional properties very similar to those of the wild-type protein. Our results reveal that, independent of its orientation, the salt-bridge is required to support efficient ATP hydrolysis, normal communication between different functional regions of the myosin head, and motor function.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
290
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
797-809
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Role of the salt-bridge between switch-1 and switch-2 of Dictyostelium myosin.
pubmed:affiliation
Max-Planck-Institut für Medizinische Forschung, Jahnstr. 29, Heidelberg, D-69120, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't