1mm8
From Proteopedia
(New page: 200px<br /><applet load="1mm8" size="450" color="white" frame="true" align="right" spinBox="true" caption="1mm8, resolution 2.8Å" /> '''Crystal structure of ...) |
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| - | [[Image:1mm8.gif|left|200px]]<br /><applet load="1mm8" size=" | + | [[Image:1mm8.gif|left|200px]]<br /><applet load="1mm8" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1mm8, resolution 2.8Å" /> | caption="1mm8, resolution 2.8Å" /> | ||
'''Crystal structure of Tn5 Transposase complexed with ME DNA'''<br /> | '''Crystal structure of Tn5 Transposase complexed with ME DNA'''<br /> | ||
==Overview== | ==Overview== | ||
| - | In this study, evidence of novel, important interactions between a | + | In this study, evidence of novel, important interactions between a hyperactive Tn5 transposon recognition end sequence and hyperactive Tn5 transposase (Tnp) are presented. A hyperactive Tn5 end sequence, the mosaic end (ME), was isolated previously. The ME and a wild-type end sequence, the outside end (OE), differ at only three positions, yet transposition on the ME is tenfold higher than on the OE in vivo. Also, transposition on the ME is much more efficient than transposition on the OE in vitro. Here, we show that the decreased activity observed for the OE is caused by a defect in paired ends complex (PEC) formation resulting from the orientation of the A-T base-pair at position 4 of this end. Efficient PEC formation requires an interaction between the C5-methyl group (C5-Me) on the non-transferred strand thymine base at position 4 (T4) and Tnp. PEC formation on nicked substrates is much less affected by the orientation of the A-T base-pair at position 4, indicating that the C5-Me group is important only for steps preceding nicking. A recently determined co-crystal structure of Tn5 Tnp with the ME is discussed and a model explaining possible roles for the base-pair at position 4 is explored. |
==About this Structure== | ==About this Structure== | ||
| - | 1MM8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with MN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1MM8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=MN:'>MN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MM8 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Lovell, S.]] | [[Category: Lovell, S.]] | ||
[[Category: Rayment, I.]] | [[Category: Rayment, I.]] | ||
| - | [[Category: Reznikoff, W | + | [[Category: Reznikoff, W S.]] |
[[Category: Steiniger-White, M.]] | [[Category: Steiniger-White, M.]] | ||
[[Category: MN]] | [[Category: MN]] | ||
[[Category: protein-dna complex]] | [[Category: protein-dna complex]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:56:40 2008'' |
Revision as of 11:56, 21 February 2008
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Crystal structure of Tn5 Transposase complexed with ME DNA
Overview
In this study, evidence of novel, important interactions between a hyperactive Tn5 transposon recognition end sequence and hyperactive Tn5 transposase (Tnp) are presented. A hyperactive Tn5 end sequence, the mosaic end (ME), was isolated previously. The ME and a wild-type end sequence, the outside end (OE), differ at only three positions, yet transposition on the ME is tenfold higher than on the OE in vivo. Also, transposition on the ME is much more efficient than transposition on the OE in vitro. Here, we show that the decreased activity observed for the OE is caused by a defect in paired ends complex (PEC) formation resulting from the orientation of the A-T base-pair at position 4 of this end. Efficient PEC formation requires an interaction between the C5-methyl group (C5-Me) on the non-transferred strand thymine base at position 4 (T4) and Tnp. PEC formation on nicked substrates is much less affected by the orientation of the A-T base-pair at position 4, indicating that the C5-Me group is important only for steps preceding nicking. A recently determined co-crystal structure of Tn5 Tnp with the ME is discussed and a model explaining possible roles for the base-pair at position 4 is explored.
About this Structure
1MM8 is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
Reference
Evidence for "unseen" transposase--DNA contacts., Steiniger-White M, Bhasin A, Lovell S, Rayment I, Reznikoff WS, J Mol Biol. 2002 Oct 4;322(5):971-82. PMID:12367522
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