Protein Family Models

This domain is found at the N-terminus of the methylase subunit of Type I DNA methyltransferases. This domain family is found in bacteria and archaea, and is typically between 123 and 138 amino acids in length. The family is found in association with Pfam:PF02384. Mutations in this region of EcoKI methyltransferase Swiss:P08957 abolish the normally strong preference of this system for methylating hemimethylated substrate [1]. The structure of this domain has been shown to be all alpha-helical. [1]. 1833555. Mutations that confer de novo activity upon a maintenance methyltransferase. Kelleher JE, Daniel AS, Murray NE;. J Mol Biol. 1991;221:431-440. (from Pfam)

Date:

2024-10-16

Restriction-modification (R-M) systems protect a bacterial cell against invasion of foreign DNA by endonucleolytic cleavage of DNA that lacks a site specific modification. The R-M system is a complex containing three polypeptides: M (this family), S (Pfam:PF01420), and R [1]. This family consists of N-6 adenine-specific DNA methylase EC:2.1.1.72 from Type I and Type IC restriction systems. These methylases have the same sequence specificity as their corresponding restriction enzymes. [1]. 9440532. A type IC restriction-modification system in Lactococcus lactis. Schouler C, Clier F, Lerayer AL, Ehrlich SD, Chopin MC;. J Bacteriol 1998;180:407-411. [2]. 9593305. Combinational variation of restriction modification specificities in Lactococcus lactis. Schouler C, Gautier M, Ehrlich SD, Chopin MC;. Mol Microbiol 1998;28:169-178. [3]. 9108149. The specificity of sty SKI, a type I restriction enzyme, implies a structure with rotational symmetry. Thorpe PH, Ternent D, Murray NE;. Nucleic Acids Res 1997;25:1694-1700. (from Pfam)

Date:

2024-10-16

type I restriction-modification system modification (M) subunit (HsdM), together with specificity (S) subunit (HsdS), forms a methyltransferase that methylates two adenine residues in complementary strands of a bipartite DNA recognition sequence

Date:

2019-02-11