Structural and Functional Analysis of the Engineered Type I DNA Methyltransferase EcoR124INT

JOURNAL OF MOLECULAR BIOLOGY

卷:398

Article

Taylor, James E. N.¹  Callow, Phil²  Swiderska, Anna¹  Kneale, G. Geoff¹ 

[1] Univ Portsmouth, Biophys Labs, Inst Biomed & Biomol Sci, Portsmouth PO1 2DT, Hants, England

[2] Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France

关键词: DNA methyltransferase;    DNA methylation;    restriction-modification;    sedimentation velocity;    small-angle neutron scattering;   

DOI  :  10.1016/j.jmb.2010.03.008

来源: Elsevier

【 摘 要 】

The Type I R-M system EcoR1241 is encoded by three genes. HsdM is responsible for modification (DNA methylation), HsdS for DNA sequence specificity and HsdR for restriction endonuclease activity. The trimeric methyltransferase (M2S) recognises the asymmetric sequence (GAAN(6)-RTCG). An engineered R-M system, denoted EcoR124I(NT), has two copies of the N-terminal domain of the HsdS subunit of EcoR1241, instead of a single S subunit with two domains, and recognises the symmetrical sequence GAAN(7)TTC. We investigate the methyltransferase activity of EcoR124I(NT), characterise the enzyme and its subunits by analytical ultracentrifugation and obtain low-resolution structural models from small-angle neutron scattering experiments using contrast variation and selective deuteration of subunits. (C) 2010 Elsevier Ltd All rights reserved

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