1mm8
From Proteopedia
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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 MN 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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