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Structural and functional analysis of the engineered type I DNA methyltransferase EcoR124I(NT).

ABSTRACT: The Type I R-M system EcoR124I 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 (M(2)S) 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 EcoR124I, 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.

SUBMITTER: Taylor JEN

PROVIDER: S-EPMC2877798 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature

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Structural and functional analysis of the engineered type I DNA methyltransferase EcoR124INT.

Taylor James E N JEN Callow Phil P Swiderska Anna A Kneale G Geoff GG

Journal of molecular biology 20100317 3

The Type I R-M system EcoR124I 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 (GAAN6RTCG). An engineered R-M system, denoted EcoR124INT, has two copies of the N-terminal domain of the HsdS subunit of EcoR124I, instead of a single S subunit with two domains, and recognises the ...[more]

PMID: 20302878

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