1Y6U

The Structure of the Excisionase (Xis) Protein from Conjugative Transposon Tn916 Provides Insights into the Regulation of Heterobivalent Tyrosine Recombinases

1Y6U の概要

• エントリーDOI: 10.2210/pdb1y6u/pdb
• NMR情報: BMRB: 6479
• 分子名称: Excisionase from transposon Tn916 (1 entity in total)
• 機能のキーワード: dna architectural protein, tyrosine recombinase, excisionase, winged-helix protein, conjugative transposon, dna binding protein
• 由来する生物種: Enterococcus faecalis
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 8389.67

構造登録者

Abbani, M.,Iwahara, M.,Clubb, R.T. (登録日: 2004-12-07, 公開日: 2005-03-15, 最終更新日: 2024-05-22)

主引用文献

Abbani, M.,Iwahara, M.,Clubb, R.T.
The structure of the excisionase (xis) protein from conjugative transposon tn916 provides insights into the regulation of heterobivalent tyrosine recombinases
J.Mol.Biol., 347:11-25, 2005

PubMed Abstract: Heterobivalent tyrosine recombinases play a prominent role in numerous bacteriophage and transposon recombination systems. Their enzymatic activities are frequently regulated at a structural level by excisionase factors, which alter the ability of the recombinase to assemble into higher-order recombinogenic nucleoprotein structures. The Tn916 conjugative transposon spreads antibiotic resistance in pathogenic bacteria and is mobilized by a heterobivalent recombinase (Tn916Int), whose activity is regulated by an excisionase factor (Tn916Xis). Unlike the well-characterized (lambda)Xis excisionase from bacteriophage lambda, Tn916Xis stimulates excision in vitro and in Escherichia coli only modestly. To gain insights into this functional difference, we have performed in vitro DNA-binding studies of Tn916Xis and Tn916Int, and we have solved the solution structure of Tn916Xis. We show that the heterobivalent Tn916Int protein is capable of bridging the DR2-type and core-type sites on the left arm of the tranpsoson. Consistent with the notion that Tn916Int is regulated only loosely, we find that Tn916Xis binding does not alter the stability of DR2-Tn916Int-core bridges or the ability of Tn916Int to recognize the arms of the transposon in vitro. Despite a high degree of divergence at the primary sequence level, we show that Tn916Xis and (lambda)Xis adopt related prokaryotic winged-helix structures. However, they differ at their C termini, with Tn916Xis replacing the flexible integrase contacting tail found in (lambda)Xis with a positively charged alpha-helix. This difference provides a structural explanation for why Tn916Xis does not interact cooperatively with its cognate integrase in vitro, and reveals how subtle changes in the winged-helix fold can modulate the functional properties of excisionase factors.

PubMed: 15733914
DOI: 10.1016/j.jmb.2005.01.019

実験手法

SOLUTION NMR