3OKG

Crystal structure of HsdS subunit from Thermoanaerobacter tengcongensis

Summary for 3OKG

• Entry DOI: 10.2210/pdb3okg/pdb
• Descriptor: Restriction endonuclease S subunits, SULFATE ION (3 entities in total)
• Functional Keywords: coiled-coil, type i methyltransferase, dna binding, dna binding protein
• Biological source: Thermoanaerobacter tengcongensis
• Total number of polymer chains: 2
• Total formula weight: 94483.66

Authors

Liang, D.,Gao, P.,Tang, Q.,An, X.,Yan, X. (deposition date: 2010-08-24, release date: 2011-05-25, Last modification date: 2024-03-20)

Primary citation

Gao, P.,Tang, Q.,An, X.,Yan, X.,Liang, D.
Structure of HsdS subunit from Thermoanaerobacter tengcongensis sheds lights on mechanism of dynamic opening and closing of type I methyltransferase
Plos One, 6:e17346-e17346, 2011

PubMed Abstract: Type I DNA methyltransferases contain one specificity subunit (HsdS) and two modification subunits (HsdM). The electron microscopy model of M.EcoKI-M₂S₁ methyltransferase shows a reasonable closed state of this clamp-like enzyme, but the structure of the open state is still unclear. The 1.95 Å crystal structure of the specificity subunit from Thermoanaerobacter tengcongensis (TTE-HsdS) shows an unreported open form inter-domain orientation of this subunit. Based on the crystal structure of TTE-HsdS and the closed state model of M.EcoKI-M₂S₁, we constructed a potential open state model of type I methyltransferase. Mutational studies indicated that two α-helices (aa30-59 and aa466-495) of the TTE-HsdM subunit are important inter-subunit interaction sites in the TTE-M₂S₁ complex. DNA binding assays also highlighted the importance of the C-terminal region of TTE-HsdM for DNA binding by the TTE-M₂S₁ complex. On the basis of structural analysis, biochemical experiments and previous studies, we propose a dynamic opening and closing mechanism for type I methyltransferase.

PubMed: 21399684
DOI: 10.1371/journal.pone.0017346

Experimental method

X-RAY DIFFRACTION (1.95 Å)