@article{0f0cf3eb1fb1429ba5174b017e13ded8,
title = "Identification of a DNA N6-Adenine Methyltransferase Complex and Its Impact on Chromatin Organization",
abstract = "DNA N6-adenine methylation (6mA) has recently been described in diverse eukaryotes, spanning unicellular organisms to metazoa. Here, we report a DNA 6mA methyltransferase complex in ciliates, termed MTA1c. It consists of two MT-A70 proteins and two homeobox-like DNA-binding proteins and specifically methylates dsDNA. Disruption of the catalytic subunit, MTA1, in the ciliate Oxytricha leads to genome-wide loss of 6mA and abolishment of the consensus ApT dimethylated motif. Mutants fail to complete the sexual cycle, which normally coincides with peak MTA1 expression. We investigate the impact of 6mA on nucleosome occupancy in vitro by reconstructing complete, full-length Oxytricha chromosomes harboring 6mA in native or ectopic positions. We show that 6mA directly disfavors nucleosomes in vitro in a local, quantitative manner, independent of DNA sequence. Furthermore, the chromatin remodeler ACF can overcome this effect. Our study identifies a diverged DNA N6-adenine methyltransferase and defines the role of 6mA in chromatin organization.",
keywords = "DNA methylation, N6-methyladenine, chromatin remodeling, nucleosome positioning, synthetic chromosomes",
author = "Beh, {Leslie Y.} and Debelouchina, {Galia T.} and Clay, {Derek M.} and Thompson, {Robert E.} and Lindblad, {Kelsi A.} and Hutton, {Elizabeth R.} and Bracht, {John R.} and Sebra, {Robert P.} and Muir, {Tom W.} and Landweber, {Laura F.}",
note = "Funding Information: We thank T. Srikumar and S. Kyin for assistance with nucleoside MS; I. Pelczer for assistance with NMR measurements of nucleoside standards; W. Wang, J. Wiggins, and J. Miller for assistance with Illumina sequencing; C.D. Allis, V. Zakian, T. Bestor, S.H. Sternberg, W. Jack, R. Neme, G. Dann, K. Jani, A. Mostafavi, and G. Liszczak for helpful discussions; I. Fernandez and A. Sobolevsky for discussions and access to FPLC equipment; and J. Wang, B. Dul, and F. Song for laboratory support. This work was funded by NIH grants R01-GM59708, R35-GM122555, and R01-GM109459 to L.F.L. and R01-GM107047 to T.W.M. L.Y.B. conceived the project, synthesized chromosomes, performed computational and experimental analysis for all figures and tables, and wrote the manuscript. G.T.D. synthesized chromosomes and prepared Xenopus histones. D.M.C. generated mta1 mutants. R.E.T. synthesized 6mA nucleoside standards for MS. K.A.L. processed raw SMRT-seq data. E.R.H. performed 6mA IP-seq. J.R.B. prepared Oxytricha DNA for SMRT-seq. R.P.S. performed SMRT-seq. T.W.M. and L.F.L. conceived the project and analyzed data. G.T.D. T.W.M. and L.F.L. edited the manuscript. The authors declare no competing interests. Funding Information: We thank T. Srikumar and S. Kyin for assistance with nucleoside MS; I. Pelczer for assistance with NMR measurements of nucleoside standards; W. Wang, J. Wiggins, and J. Miller for assistance with Illumina sequencing; C.D. Allis, V. Zakian, T. Bestor, S.H. Sternberg, W. Jack, R. Neme, G. Dann, K. Jani, A. Mostafavi, and G. Liszczak for helpful discussions; I. Fernandez and A. Sobolevsky for discussions and access to FPLC equipment; and J. Wang, B. Dul, and F. Song for laboratory support. This work was funded by NIH grants R01-GM59708 , R35-GM122555 , and R01-GM109459 to L.F.L. and R01-GM107047 to T.W.M. Publisher Copyright: {\textcopyright} 2019 Elsevier Inc.",
year = "2019",
month = jun,
day = "13",
doi = "10.1016/j.cell.2019.04.028",
language = "English (US)",
volume = "177",
pages = "1781--1796.e25",
journal = "Cell",
issn = "0092-8674",
publisher = "Cell Press",
number = "7",
}