Abstract
The functional efficacy of colocalized, linked protein domains is dependent on linker flexibility and system compaction. However, the detailed characterization of these properties in aqueous solution presents an enduring challenge. Here, we employ a novel, to our knowledge, combination of complementary techniques, including small-angle neutron scattering, neutron spin-echo spectroscopy, and all-atom molecular dynamics and coarse-grained simulation, to identify and characterize in detail the structure and dynamics of a compact form of mercuric ion reductase (MerA), an enzyme central to bacterial mercury resistance. MerA possesses metallochaperone-like N-terminal domains (NmerA) tethered to its catalytic core domain by linkers. The NmerA domains are found to interact principally through electrostatic interactions with the core, leashed by the linkers so as to subdiffuse on the surface over an area close to the core C-terminal Hg(II)-binding cysteines. How this compact, dynamical arrangement may facilitate delivery of Hg(II) from NmerA to the core domain is discussed.
Original language | English |
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Pages (from-to) | 393-400 |
Number of pages | 8 |
Journal | Biophysical Journal |
Volume | 107 |
Issue number | 2 |
DOIs | |
State | Published - Jul 15 2014 |
Funding
We acknowledge support from National Science Foundation (NSF) grant MCB-0842871 and grants ER65062 and ER65063 from the Subsurface Biogeochemical Research Program, Office of Biological and Environmental Research, U.S. Department of Energy (DOE). This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under contract No. DE-AC05-00OR22725.