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

Homologues of the Escherichia coli Eco57I restriction-modification methylase are found in several phylogenetically diverse bacteria. The structure of TaqI has been solved [1]. [1]. 1334261. Cloning and sequence analysis of the genes coding for Eco57I type IV restriction-modification enzymes. Janulaitis A, Vaisvila R, Timinskas A, Klimasauskas S, Butkus V;. Nucleic Acids Res 1992;20:6051-6056. [2]. 8995524. Differential binding of S-adenosylmethionine S-adenosylhomocysteine and Sinefungin to the adenine-specific DNA methyltransferase M.TaqI. Schluckebier G, Kozak M, Bleimling N, Weinhold E, Saenger W;. J Mol Biol. 1997;265:56-67. (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

This domain is the methyltransferase domain found in ribosomal RNA large subunit methyltransferase K/L from Escherichia coli (RmlKL), tRNA (guanine(10)-N2)-dimethyltransferase from Methanocaldococcus jannaschii and similar proteins, which have a THUMP domain at the N-terminal [1-4]. [1]. 11295541. THUMP - a predicted RNA-binding domain shared by 4-thiouridine, pseudouridine synthases and RNA methylases. Aravind L, Koonin EV;. Trends Biochem Sci 2001;26:215-217. [2]. 16343540. Crystal structure of Bacillus anthracis ThiI, a tRNA-modifying enzyme containing the predicted RNA-binding THUMP domain. Waterman DG, Ortiz-Lombardia M, Fogg MJ, Koonin EV, Antson AA;. J Mol Biol. 2006;356:97-110. [3]. 17010378. Identification of Escherichia coli m2G methyltransferases: I. the ycbY gene encodes a methyltransferase specific for G2445 of the 23 S rRNA. Lesnyak DV, Sergiev PV, Bogdanov AA, Dontsova OA;. J Mol Biol. 2006;364:20-25. [4]. 22362734. Structure of the bifunctional methyltransferase YcbY (RlmKL) that adds the m7G2069 and m2G2445 modifications in Escherichia coli 23S rRNA. Wang KT, Desmolaize B, Nan J, Zhang XW, Li LF, Douthwaite S, Su XD;. Nucleic Acids Res. 2012;40:5138-5148. (from Pfam)

Date:

2024-10-16

class I SAM-dependent DNA methyltransferase catalyzes the methylation of a specific DNA substrate using S-adenosyl-L-methionine (SAM or AdoMet) as the methyl donor similar to type I restriction-modification system modification (M) subunit (HsdM), which together with specificity (S) subunit (HsdS), forms a methyltransferase that methylates two adenine residues in complementary strands of a bipartite DNA recognition sequence

Date:

2022-08-10