1Q0T

Ternary Structure of T4DAM with AdoHcy and DNA

Summary for 1Q0T

• Entry DOI: 10.2210/pdb1q0t/pdb
• Related: 1Q0S
• Descriptor: 5'-D(*AP*CP*AP*GP*GP*AP*TP*CP*CP*TP*GP*T)-3', DNA adenine methylase, IODIDE ION, ... (4 entities in total)
• Functional Keywords: t4dam, methyltransferase, dna, transferase-dna complex, transferase/dna
• Biological source: Enterobacteria phage T4
• Total number of polymer chains: 4
• Total formula weight: 69275.05

Authors

Yang, Z.,Horton, J.R.,Zhou, L.,Zhang, X.J.,Dong, A.,Zhang, X.,Schlagman, S.L.,Kossykh, V.,Hattman, S.,Cheng, X. (deposition date: 2003-07-17, release date: 2003-09-23, Last modification date: 2024-02-14)

Primary citation

Yang, Z.,Horton, J.R.,Zhou, L.,Zhang, X.J.,Dong, A.,Zhang, X.,Schlagman, S.L.,Kossykh, V.,Hattman, S.,Cheng, X.
Structure of the bacteriophage T4 DNA adenine methyltransferase
Nat.Struct.Biol., 10:849-855, 2003

PubMed Abstract: DNA-adenine methylation at certain GATC sites plays a pivotal role in bacterial and phage gene expression as well as bacterial virulence. We report here the crystal structures of the bacteriophage T4Dam DNA adenine methyltransferase (MTase) in a binary complex with the methyl-donor product S-adenosyl-L-homocysteine (AdoHcy) and in a ternary complex with a synthetic 12-bp DNA duplex and AdoHcy. T4Dam contains two domains: a seven-stranded catalytic domain that harbors the binding site for AdoHcy and a DNA binding domain consisting of a five-helix bundle and a beta-hairpin that is conserved in the family of GATC-related MTase orthologs. Unexpectedly, the sequence-specific T4Dam bound to DNA in a nonspecific mode that contained two Dam monomers per synthetic duplex, even though the DNA contains a single GATC site. The ternary structure provides a rare snapshot of an enzyme poised for linear diffusion along the DNA.

PubMed: 12937411
DOI: 10.1038/nsb973

Experimental method

X-RAY DIFFRACTION (3.1 Å)