Solution structure of dimeric Mnt repressor (1-76).Burgering, M.J., Boelens, R., Gilbert, D.E., Breg, J.N., Knight, K.L., Sauer, R.T., Kaptein, R.
(1994) Biochemistry 33: 15036-15045
- PubMed: 7999761
- PubMed Abstract:
- Structure of Arc Repressor in Solution: Evidence for a Family of B-Sheet DNA-Binding Protein
Breg, J.N.,Van Opheusden, J.H.J.,Burgering, M.J.M.,Boelens, R.,Kaptein, R.
(1990) Nature 346: 586
- Observation of Inter-Subunit Noes in a Dimeric P22 Mnt Repressor Mutant by a Time-Shared [15N, 13C] Double Half Filter Technique
Burgering, M.J.M.,Boelens, R.,Kaptein, R.
(1993) J.Biomol.NMR 3: 709
- The Mnt Repressor of Bacteriophage P22: Role of the C-Terminal Residues in Operator Binding and Tetramer Formation
Knight, K.L.,Sauer, R.T.
(1988) Biochemistry 27: 2088
Wild-type Mnt repressor of Salmonella bacteriophage P22 is a tetrameric protein of 82 residues per monomer. A C-terminal deletion mutant of the repressor denoted Mnt (1-76) is a dimer in solution. The structure of this dimer has been determined using ...
Wild-type Mnt repressor of Salmonella bacteriophage P22 is a tetrameric protein of 82 residues per monomer. A C-terminal deletion mutant of the repressor denoted Mnt (1-76) is a dimer in solution. The structure of this dimer has been determined using NMR. The NMR assignments of the majority of the 1H, 15N, and 13C resonances were obtained using 2D and triple-resonance 3D techniques. Elements of secondary structure were identified on the basis of characteristic sequential and medium range NOEs. For the structure determination more than 1000 NOEs per monomer were obtained, and structures were generated using distance geometry and restrained simulated annealing calculations. The discrimination of intra- vs intermonomer NOEs was based upon the observation of intersubunit NOEs in [15N,13C] double half-filtered NOESY experiments. The N-terminal part of Mnt (residues 1-44), which shows a 40% sequence homology with the Arc repressor, has a similar secondary and tertiary structure. Mnt (1-76) continues with a loop region of irregular structure, a third alpha-helix, and a random coil C-terminal peptide. Analysis of the secondary structure NOEs, the exchange rates, and the backbone chemical shifts suggests that the carboxy-terminal third helix is less stable than the remainder of the protein, but the observation of intersubunit NOEs for this part of the protein enables the positioning of this helix. The rsmd's between the backbone atoms of the N-terminal part of the Mnt repressor (residues 5-43, 5'-43') and the Arc repressor is 1.58 A, and between this region and the corresponding part of the MetJ repressor 1.43 A.
Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands.