Klimasauskas, S., Kumar, S., Roberts, R. J., Cheng, X. D. (January 1994) Hhal Methyltransferase Flips Its Target Base out of the DNA Helix. Cell, 76 (2). pp. 357-369. ISSN 0092-8674
Abstract
The crystal structure has been determined at 2.8 A resolution for a chemically-trapped covalent reaction intermediate between the HhaI DNA cytosine-5-methyltransferase, S-adenosyl-L-homocysteine, and a duplex 13-mer DNA oligonucleotide containing methylated 5-fluorocytosine at its target. The DNA is located in a cleft between the two domains of the protein and has the characteristic conformation of B-form DNA, except for a disrupted G-C base pair that contains the target cytosine. The cytosine residue has swung completely out of the DNA helix and is positioned in the active site, which itself has undergone a large conformational change. The DNA is contacted from both the major and the minor grooves, but almost all base-specific interactions between the enzyme and the recognition bases occur in the major groove, through two glycine-rich loops from the small domain. The structure suggests how the active nucleophile reaches its target, directly supports the proposed mechanism for cytosine-5 DNA methylation, and illustrates a novel mode of sequence-specific DNA recognition.
| Item Type: | Paper |
|---|---|
| Uncontrolled Keywords: | COLI THYMIDYLATE SYNTHASE CRYSTAL-STRUCTURE MACROMOLECULAR CRYSTALLOGRAPHY DETERMINES METHYLATION DIFFRACTION ANALYSIS RECOGNIZING DOMAINS MAMMALIAN NUCLEI MISMATCH REPAIR GENE-EXPRESSION MECHANISM |
| Subjects: | bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > DNA binding protein Investigative techniques and equipment > x ray crystallography |
| CSHL Authors: | |
| Communities: | CSHL labs |
| Depositing User: | Matt Covey |
| Date: | January 1994 |
| Date Deposited: | 04 May 2015 16:06 |
| Last Modified: | 04 May 2015 16:06 |
| Related URLs: | |
| URI: | https://repository.cshl.edu/id/eprint/31481 |
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