Tanmay A M Bharat / David Zbaida / Miriam Eisenstein / Ziv Frankenstein / Tevie Mehlman / Lev Weiner / Carlos Oscar S Sorzano / Yoav Barak / Shira Albeck / John A G Briggs / Sharon G Wolf / Michael Elbaum /
PubMed 要旨
Agrobacterium is known for gene transfer to plants. In addition to a linear ssDNA oligonucleotide, Agrobacterium tumefaciens secretes an abundant ssDNA-binding effector, VirE2. In many ways VirE2 ...Agrobacterium is known for gene transfer to plants. In addition to a linear ssDNA oligonucleotide, Agrobacterium tumefaciens secretes an abundant ssDNA-binding effector, VirE2. In many ways VirE2 adapts the conjugation mechanism to transform the eukaryotic host. The crystal structure of VirE2 shows two compact domains joined by a flexible linker. Bound to ssDNA, VirE2 forms an ordered solenoidal shell, or capsid known as the T-complex. Here, we present a three-dimensional reconstruction of the VirE2-ssDNA complex using cryo-electron microscopy and iterative helical real-space reconstruction. High-resolution refinement was not possible due to inherent heterogeneity in the protein structure. By a combination of computational modeling, chemical modifications, mass spectroscopy, and electron paramagnetic resonance, we found that the N-terminal domain is tightly constrained by both tangential and longitudinal links, while the C terminus is weakly constrained. The quaternary structure is thus rigidly assembled while remaining locally flexible. This flexibility may be important in accommodating substrates without sequence specificity.
EMDB-2339, PDB-4blf: Variable internal flexibility characterizes the helical capsid formed by Agrobacterium VirE2 protein on single-stranded DNA. 手法: EM (らせん対称) / 解像度: 20.0 Å
由来
Agrobacterium fabrum str. C58 (バクテリア)
agrobacterium tumefaciens (植物への病原性)
キーワード
DNA BINDING PROTEIN / TCOMPLEX / AGROBACTERIUM / HELICAL RECONSTRUCTION