TY - JOUR
T1 - Variable internal flexibility characterizes the helical capsid formed by agrobacterium VirE2 protein on single-stranded DNA
AU - Bharat, Tanmay A. M.
AU - Zbaida, David
AU - Eisenstein, Miriam
AU - Frankenstein, Ziv
AU - Mehlman, Tevie
AU - Weiner, Lev
AU - Sorzano, Carlos Oscar S.
AU - Barak, Yoav
AU - Albeck, Shira
AU - Briggs, John A. G.
AU - Wolf, Sharon G.
AU - Elbaum, Michael
N1 - FEBS summer fellowship program; Israel Science Foundation-Bikura program; European Research Council; Gerhardt M.J. Schmidt Minerva Center for Supramolecular Architecture; Harold Perlman familyM.E. and S.G.W. acknowledge valuable discussions with Pawel Penczek. T.A.M.B. was supported initially by the FEBS summer fellowship program. We thank Dalit Merhav for her enthusiastic support in mass spectroscopy measurements. This work was supported in part by grants from the Israel Science Foundation-Bikura program and the European Research Council. Electron microscopy was performed at the Irving and Cherna Moscowitz Center for Nano and Bio- Nano Imaging of the Weizmann Institute of Science. We acknowledge support from the Gerhardt M.J. Schmidt Minerva Center for Supramolecular Architecture and the historical generosity of the Harold Perlman family.
PY - 2013/7/2
Y1 - 2013/7/2
N2 - 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.
AB - 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.
UR - https://www.scopus.com/pages/publications/84879839894
U2 - 10.1016/j.str.2013.04.027
DO - 10.1016/j.str.2013.04.027
M3 - Article
SN - 0969-2126
VL - 21
SP - 1158
EP - 1167
JO - Structure
JF - Structure
IS - 7
ER -