Linked Life Data

15035645

Source:http://linkedlifedata.com/resource/pubmed/id/15035645

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2004-3-23
pubmed:abstractText
In most eukaryotes, the histone methyltransferase SU(VAR)3-9 and its orthologues play a major role in the function of centromeric heterochromatin. Although the methyltransferase domain is required for the formation of a fully functional centromere, mutations within other regions of the gene such as the N-terminus also have a strong impact on its in vivo function. To analyze the contribution of the N-terminus on the methyltransferase activity, we have expressed the full-length Drosophila SU(VAR)3-9 (dSU(VAR)3-9) together with various N-terminal deletions in Escherichia coli and analyzed the structural and enzymatic properties of the purified recombinant enzymes. Full-length dSU(VAR)3-9 specifically methylates lysine 9 within histone H3 on peptides, on intact histones, and, to a lesser extent, on nucleosomes. A detailed analysis of the reaction products shows that dSU(VAR)3-9 adds two methyl groups to an unmethylated H3 tail peptide in a nonprocessive manner. The full-length enzyme elutes with an apparent molecular weight of 160 kDa from a gel filtration column, which indicates the formation of a dimer. This property is dependent on an intact N-terminus. In contrast to the full-length enzymes, proteins lacking the N-terminus fail to dimerize, and show a 10-fold lower specific activity and a linear dependence of methyltransferase activity on enzyme concentration. A N-terminal peptide containing amino acids 1-152 of dSU(VAR)3-9 is sufficient to mediate this interaction in vitro. The dimerization of dSU(VAR)3-9 and the subsequent increase of its methyltransferase activity provide a starting point to understand the molecular details of the formation of heterochromatic structures in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3740-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:15035645-Amino Acid Sequence, pubmed-meshheading:15035645-Animals, pubmed-meshheading:15035645-Catalysis, pubmed-meshheading:15035645-Dimerization, pubmed-meshheading:15035645-Drosophila Proteins, pubmed-meshheading:15035645-Drosophila melanogaster, pubmed-meshheading:15035645-Enzyme Activation, pubmed-meshheading:15035645-Histone-Lysine N-Methyltransferase, pubmed-meshheading:15035645-Histones, pubmed-meshheading:15035645-Isoenzymes, pubmed-meshheading:15035645-Kinetics, pubmed-meshheading:15035645-Lysine, pubmed-meshheading:15035645-Methylation, pubmed-meshheading:15035645-Methyltransferases, pubmed-meshheading:15035645-Molecular Sequence Data, pubmed-meshheading:15035645-Peptide Fragments, pubmed-meshheading:15035645-Protein Binding, pubmed-meshheading:15035645-Protein Methyltransferases, pubmed-meshheading:15035645-Protein Processing, Post-Translational, pubmed-meshheading:15035645-Recombinant Proteins, pubmed-meshheading:15035645-Sequence Deletion
pubmed:year
2004
pubmed:articleTitle
The N-terminus of Drosophila SU(VAR)3-9 mediates dimerization and regulates its methyltransferase activity.
pubmed:affiliation
Adolf-Butenandt Institute, Department of Molecular Biology, Ludwig-Maximillians University of Munich, Schillerstrasse 44, 80336 Munich, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't