1qey
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NMR STRUCTURE DETERMINATION OF THE TETRAMERIZATION DOMAIN OF THE MNT REPRESSOR: AN ASYMMETRIC A-HELICAL ASSEMBLY IN SLOW EXCHANGE
OverviewOverview
The tetrameric Mnt repressor is involved in the genetic switch between the, lysogenic and lytic growth of Salmonella bacteriophage P22. The solution, structure of its C-terminal tetramerization domain, which holds together, the two dimeric DNA-binding domains, has been determined by NMR, spectroscopy. This structure reveals an assembly of four alpha-helical, subunits, consisting of a dimer of two antiparallel coiled coils with a, unique right-handed twist. The superhelical winding is considerably, stronger and the interhelical separation closer than those found in the, well-known left-handed coiled coils in fibrous proteins and leucine, zippers. An unusual asymmetry arises between the two monomers that, comprise one right-handed coiled coil. A difference in the packing to the, adjacent monomer of the other coiled coil occurs with an offset of two, helical turns. The two asymmetric monomers within each coiled coil, interconvert on a time scale of seconds. Both with respect to symmetry and, handedness of helical packing, the C2 symmetric four-helix bundle of Mnt, differs from other oligomerization domains that assemble DNA-binding, modules, such as that in the tumor suppressor p53 and the E. coli lac, repressor.
About this StructureAbout this Structure
1QEY is a Single protein structure of sequence from Yersinia phage py54. Full crystallographic information is available from OCA.
ReferenceReference
The tetramerization domain of the Mnt repressor consists of two right-handed coiled coils., Nooren IM, Kaptein R, Sauer RT, Boelens R, Nat Struct Biol. 1999 Aug;6(8):755-9. PMID:10426954
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