Solution structure of the I gamma subdomain of the Mu end DNA-binding domain of phage Mu transposase.
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.
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Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA.
Schumacher
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Mizuuchi
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Gronenborn
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Clore
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D000595:Amino Acid Sequence; D010583:Bacteriophage mu / Q000201:enzymology*; D004279:DNA, Viral / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D019077:Helix-Turn-Helix Motifs; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed / Q000235:genetics; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D017384:Sequence Deletion / Q000235:genetics; D019895:Transposases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D004279:DNA, Viral; D018398:Homeodomain Proteins; D011994:Recombinant Proteins; D019895:Transposases