Solution structure of the I gamma subdomain of the Mu end DNA-binding domain of phage Mu transposase

J Mol Biol. 1997 Oct 17;273(1):19-25. doi: 10.1006/jmbi.1997.1312.


The MuA transposase of phase Mu is a large modular protein that plays a central role in transposition. We show that the Mu end DNA-binding domain, I beta gamma, which is responsible for binding the DNA attachment sites at each end of the Mu genome, comprises two subdomains, I beta and I gamma, that are structurally autonomous and do not interact with each other in the absence of DNA. The solution structure of the I gamma subdomain has been determined by multidimensional NMR spectroscopy. The structure of I gamma comprises a four helix bundle and, despite the absence of any significant sequence identity, the topology of the first three helices is very similar to that of the homeodomain family of helix-turn-helix DNA-binding proteins. The helix-turn-helix motif of I gamma, however, differs from that of the homeodomains in so far as the loop is longer and the second helix is shorter, reminiscent of that in the POU-specific domain.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Bacteriophage mu / enzymology*
  • DNA, Viral / metabolism*
  • Escherichia coli / genetics
  • Gene Expression / genetics
  • Helix-Turn-Helix Motifs
  • Homeodomain Proteins / chemistry
  • Homeodomain Proteins / genetics
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed / genetics
  • Protein Structure, Secondary
  • Recombinant Proteins / chemistry
  • Sequence Deletion / genetics
  • Transposases / chemistry*
  • Transposases / genetics
  • Transposases / metabolism


  • DNA, Viral
  • Homeodomain Proteins
  • Recombinant Proteins
  • Transposases