1yhb
From Proteopedia
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CRYSTAL STRUCTURES OF Y41H AND Y41F MUTANTS OF GENE V PROTEIN FROM FF PHAGE SUGGEST POSSIBLE PROTEIN-PROTEIN INTERACTIONS IN GVP-SSDNA COMPLEX
Overview
Gene V protein (GVP) encoded by the filamentous phage Ff (M13, fl, fd) is, a homodimeric protein of 87 amino acids that binds to single-stranded DNA, (ssDNA) nonspecifically and cooperatively. The structure (monoclinic C2, form) of the wild-type protein has been determined and refined at 1.8-A, resolution [Skinner et al. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 2071-2075]. The monomer structure consists of a somewhat distorted, five-stranded beta-barrel core with three prominent loops: a DNA-binding, loop, a dyad loop, and a dimer contact loop. The amino acid residue at, position 41 plays an important role in the dimer-dimer interactions of the, protein-ssDNA complex. Two Y41 mutant structures have been studied by, X-ray crystallography. The Y41F GVP structure has been refined to an, R-factor of 0.180 at 2.2-A resolution and is very similar to the wild-type, (wt) structure (rmsd of all C alpha atoms = 0.30 A). In contrast, Y41H GVP, forms a new crystal lattice in the space group P2(1)2(1)2(1) with a =, 77.18 A, b = 84.17 A, and c = 28.62 A. Its structure has been solved by, the molecular replacement method and refined to an R-factor of 0.170 at, 2.5-A resolution. The two monomers of Y41H are crystallographically, independent, and their structures remain similar to wt-GVP but with, significant differences, particularly in the DNA-binding hairpin region., In both crystals, the loop (residues 36-43) that contains the Y41 residue, is involved in the crystal dimer packings but in a different manner. The, dimer-dimer contacts found in the wt-GVP crystal may be important for GVP, aggregation in the absence of DNA. In the presence of DNA, the dimer-dimer, contacts may switch to the type found in the Y41H crystal, allowing the, GVP-ssDNA complex to form cooperatively. A model of the complex, consistent with existing biochemical and biophysical data, has been, constructed from those crystal packing data.
About this Structure
1YHB is a Single protein structure of sequence from Bacteriophage f1. Full crystallographic information is available from OCA.
Reference
Crystal structures of Y41H and Y41F mutants of gene V protein from Ff phage suggest possible protein-protein interactions in the GVP-ssDNA complex., Guan Y, Zhang H, Konings RN, Hilbers CW, Terwilliger TC, Wang AH, Biochemistry. 1994 Jun 28;33(25):7768-78. PMID:8011642
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