9mht
From Proteopedia
(New page: 200px<br /><applet load="9mht" size="450" color="white" frame="true" align="right" spinBox="true" caption="9mht, resolution 2.39Å" /> '''CYTOSINE-SPECIFIC ME...) |
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| - | [[Image:9mht.gif|left|200px]]<br /><applet load="9mht" size=" | + | [[Image:9mht.gif|left|200px]]<br /><applet load="9mht" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="9mht, resolution 2.39Å" /> | caption="9mht, resolution 2.39Å" /> | ||
'''CYTOSINE-SPECIFIC METHYLTRANSFERASE HHAI/DNA COMPLEX'''<br /> | '''CYTOSINE-SPECIFIC METHYLTRANSFERASE HHAI/DNA COMPLEX'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Three structures have been determined for complexes between HhaI | + | Three structures have been determined for complexes between HhaI methyltransferase (M.HhaI) and oligonucleotides containing a G:A, G:U or G:AP (AP = abasic or apurinic/apyrimidinic) mismatch at the target base pair. The mismatched adenine, uracil and abasic site are all flipped out of the DNA helix and located in the enzyme's active-site pocket, adopting the same conformation as in the flipped-out normal substrate. These results, particularly the flipped-out abasic deoxyribose sugar, provide insight into the mechanism of base flipping. If the process involves the protein pushing the base out of the helix, then the push must take place not on the base, but rather on the sugar-phosphate backbone. Thus rotation of the DNA backbone is probably the key to base flipping. |
==About this Structure== | ==About this Structure== | ||
| - | 9MHT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Haemophilus_haemolyticus Haemophilus haemolyticus] with SAH as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Deleted_entry Deleted entry], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.73 2.1.1.73] Full crystallographic information is available from [http:// | + | 9MHT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Haemophilus_haemolyticus Haemophilus haemolyticus] with <scene name='pdbligand=SAH:'>SAH</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Deleted_entry Deleted entry], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.73 2.1.1.73] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9MHT OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Cheng, X.]] | [[Category: Cheng, X.]] | ||
| - | [[Category: Gara, M | + | [[Category: Gara, M O.]] |
| - | [[Category: Horton, J | + | [[Category: Horton, J R.]] |
| - | [[Category: Roberts, R | + | [[Category: Roberts, R J.]] |
[[Category: SAH]] | [[Category: SAH]] | ||
[[Category: complex (methyltransferase/ dna)]] | [[Category: complex (methyltransferase/ dna)]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:18:49 2008'' |
Revision as of 17:18, 21 February 2008
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CYTOSINE-SPECIFIC METHYLTRANSFERASE HHAI/DNA COMPLEX
Overview
Three structures have been determined for complexes between HhaI methyltransferase (M.HhaI) and oligonucleotides containing a G:A, G:U or G:AP (AP = abasic or apurinic/apyrimidinic) mismatch at the target base pair. The mismatched adenine, uracil and abasic site are all flipped out of the DNA helix and located in the enzyme's active-site pocket, adopting the same conformation as in the flipped-out normal substrate. These results, particularly the flipped-out abasic deoxyribose sugar, provide insight into the mechanism of base flipping. If the process involves the protein pushing the base out of the helix, then the push must take place not on the base, but rather on the sugar-phosphate backbone. Thus rotation of the DNA backbone is probably the key to base flipping.
About this Structure
9MHT is a Single protein structure of sequence from Haemophilus haemolyticus with as ligand. Active as Deleted entry, with EC number 2.1.1.73 Full crystallographic information is available from OCA.
Reference
Structures of HhaI methyltransferase complexed with substrates containing mismatches at the target base., O'Gara M, Horton JR, Roberts RJ, Cheng X, Nat Struct Biol. 1998 Oct;5(10):872-7. PMID:9783745
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