Linked Life Data

17150753

Source:http://linkedlifedata.com/resource/pubmed/id/17150753

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
49
pubmed:dateCreated
2006-12-7
pubmed:abstractText
Transfer RNA (Gm18) methyltransferase (TrmH, EC 2.1.1.34) catalyzes the transfer of a methyl group from S-adenosyl-L-methionine (AdoMet) to the 2'-OH of the ribose of guanosine at position 18 in the D-loop of tRNA. The methyl group donor, AdoMet, is converted to S-adenosyl-L-homocysteine (AdoHcy) in the reaction. Recently, we determined the crystal structures of the AdoMet-bound and apo-forms of TrmH from Thermus thermophilus HB8. Based on the crystal structures, we carried out site-directed mutagenesis to clarify the functions of the conserved amino acid residues among SpoU RNA methyltransferases. During the course of the study, we found that the subunit structure of the wild-type TrmH changed according to the presence or absence of AdoMet analogues. In the absence of AdoMet or AdoHcy, the enzyme forms a homodimer. However, the addition of AdoMet induced the formation of a tetramer structure. Furthermore, the addition of AdoHcy caused the dissociation of subunits and gave rise to a monomer structure. These findings suggest that the dissociation of tRNA from the tRNA-enzyme complex after the methyl-transfer reaction is caused by the dissociation of enzyme subunits. In this meeting, we discuss the relationship between the catalytic mechanism and the change of the subunit structure of TrmH.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1746-8272
pubmed:author
pubmed:issnType
Electronic
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
301-2
pubmed:dateRevised
2007-9-19
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Structural change of tRNA (Gm18) methyltransferase by binding of methyl donor analogues.
pubmed:affiliation
Department of Applied Chemistry, Faculty of Engineering, Ehime University, Bunkyo 3, Matsuyama 790-8577, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't