Jump to ContentJump to Main Navigation
Show Summary Details

Biological Chemistry

Editor-in-Chief: Brüne, Bernhard

Editorial Board Member: Buchner, Johannes / Lei, Ming / Ludwig, Stephan / Sies, Helmut / Turk, Boris / Wittinghofer, Alfred


SCImago Journal Rank (SJR) 2015: 1.607
Source Normalized Impact per Paper (SNIP) 2015: 0.751
Impact per Publication (IPP) 2015: 2.609

249,00 € / $374.00 / £187.00*

Online
ISSN
1437-4315
See all formats and pricing

 


 
 

Select Volume and Issue

Issues

30,00 € / $42.00 / £23.00

Get Access to Full Text

Functional analysis of amino acid residues at the dimerisation interface of KpnI DNA methyltransferase

Shivakumara Bheemanaik1 / Janusz M. Bujnicki2 / Valakunja Nagaraja3 / Desirazu N. Rao4

1.

2.

3.

4.

Corresponding author

Citation Information: Biological Chemistry. Volume 387, Issue 5, Pages 515–523, ISSN (Online) 1437-4315, ISSN (Print) 1431-6730, DOI: 10.1515/BC.2006.067, June 2006

Publication History

Received:
December 14, 2005
Accepted:
February 24, 2006
Published Online:
2006-06-01

Abstract

KpnI DNA-(N 6-adenine) methyltransferase (M.KpnI) recognises the sequence 5′-GGTACC-3′ and transfers the methyl group from S-adenosyl-L-methionine (AdoMet) to the N6 position of the adenine residue in each strand. Earlier studies have shown that M.KpnI exists as a dimer in solution, unlike most other MTases. To address the importance of dimerisation for enzyme function, a three-dimensional model of M.KpnI was obtained based on protein fold-recognition analysis, using the crystal structures of M.RsrI and M.MboIIA as templates. Residues I146, I161 and Y167, the side chains of which are present in the putative dimerisation interface in the model, were targeted for site-directed mutagenesis. Methylation and in vitro restriction assays showed that the mutant MTases are catalytically inactive. Mutation at the I146 position resulted in complete disruption of the dimer. The replacement of I146 led to drastically reduced DNA and cofactor binding. Substitution of I161 resulted in weakening of the interaction between monomers, leading to both monomeric and dimeric species. Steady-state fluorescence measurements showed that the wild-type KpnI MTase induces structural distortion in bound DNA, while the mutant MTases do not. The results establish that monomeric MTase is catalytically inactive and that dimerisation is an essential event for M.KpnI to catalyse the methyl transfer reaction.

Keywords: DNA methyltransferase; KpnI DNA methyltransferase; S-adenosyl-l-methionine; target recognition domain

Citing Articles

Here you can find all Crossref-listed publications in which this article is cited. If you would like to receive automatic email messages as soon as this article is cited in other publications, simply activate the “Citation Alert” on the top of this page.

[1]
Eleanor Y.M. Bonnist, Kirsten Liebert, David T.F. Dryden, Albert Jeltsch, and Anita C. Jones
Biophysical Chemistry, 2012, Volume 160, Number 1, Page 28
[2]
Urulangodi Kunhiraman Madhusoodanan and Desirazu N Rao
Critical Reviews in Biochemistry and Molecular Biology, 2010, Volume 45, Number 2, Page 125
[3]
Ernst G. Malygin, Alexey A. Evdokimov, and Stanley Hattman
Biological Chemistry, 2009, Volume 390, Number 9
[4]
M. A. Carpenter and A. S. Bhagwat
Nucleic Acids Research, 2008, Volume 36, Number 16, Page 5417

Comments (0)

Please log in or register to comment.