Linked Life Data

16621600

Source:http://linkedlifedata.com/resource/pubmed/id/16621600

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2006-10-9
pubmed:abstractText
The AAA family proteins usually form a hexameric ring structure. The ATP-binding pocket, which is located at the interface of subunits in the hexamer, consists of three functionally important motifs, the Walker A and B motifs, and the second region of homology (SRH). It is well known that Walker A and B motifs mediate ATP binding and hydrolysis, respectively. Highly conserved arginine residues in the SRH have been proposed to function as arginine fingers, which interact with the gamma-phosphate of bound ATP. To elucidate the mechanism of ATP hydrolysis, we prepared several mutants of the Caenorhabditis elegans fidgetin homologue FIGL-1 carrying a mutation in each of the above-mentioned three motifs. None of the constructed mutants showed ATPase activity. All the mutants except for K362A were able to bind ATP. A decrease in the ATPase activity by mixing wild-type and each mutant subunits was caused by the formation of hetero-hexamers. Mixtures of E416A and R471A, or N461A and R471A led to the formation of hetero-hexamers with partially restored ATPase activities, providing direct, firm evidence for the intersubunit catalysis model. In addition, based on the results obtained with mixtures of K362A with wild-type or R471A subunits, we propose that a conformational change upon ATP binding is required for proper orientation of the arginine fingers, which is essential for efficient hydrolysis of ATP bound to the neighboring subunit.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1047-8477
pubmed:author
pubmed:issnType
Print
pubmed:volume
156
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
93-100
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Mutational analysis of the functional motifs in the ATPase domain of Caenorhabditis elegans fidgetin homologue FIGL-1: firm evidence for an intersubunit catalysis mechanism of ATP hydrolysis by AAA ATPases.
pubmed:affiliation
Division of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't