LA  - eng
AID - BPJ3262 [pii]
AID - 10.1016/j.bpj.2011.11.006 [doi]
PMC - PMC3244067
PMID- 22208199
VI  - 101
IP  - 12
PG  - 2999-3007
DP  - 2011 Dec 21
PHST- 2011/08/23 [received]
PHST- 2011/11/01 [accepted]
IS  - 0006-3495 (Print)
IS  - 1542-0086 (Electronic)
TI  - Atomistic Ensemble Modeling and Small-Angle Neutron Scattering of Intrinsically Disordered Protein Complexes: Applied to Minichromosome Maintenance Protein
AB  - The minichromosome maintenance (MCM) proteins are thought to function as the replicative helicases in archaea and eukarya. In this work we determined the solution structure of the N-terminal portion of the MCM complex from the archaeon Methanothermobacter thermautotrophicus (N-mtMCM) in the presence and absence of DNA using small-angle neutron scattering (SANS). N-mtMCM is a multimeric protein complex that consists of 12 monomers, each of which contains three distinct domains and two unstructured regions. Using an all-atom approach incorporating modern force field and Monte Carlo methods to allow the unstructured regions of each monomer to be varied independently, we generated an ensemble of biologically relevant structures for the complex. An examination of the subsets of structures that were most consistent with the SANS data revealed that large movements between the three domains of N-mtMCM can occur in solution. Furthermore, changes in the SANS curves upon DNA binding could be correlated to the motion of a particular N-mtMCM domain. These results provide structural support to the previously reported biochemical observations that large domain motions are required for the activation of the MCM helicase in archaea and eukarya. The methods developed here for N-mtMCM solution structure modeling should be suitable for other large protein complexes with unstructured flexible regions. 
AU  - Krueger S
FAU - Krueger, S
AD  - National Institute of Standards and Technology Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland
AU  - Shin J
FAU - Shin, J-H
AD  - Division of Applied Biology and Chemistry, College of Agriculture and Life Sciences, Kyungpook National University, Daegu, Republic of Korea
AU  - Raghunandan S
FAU - Raghunandan, S
AD  - National Institute of Standards and Technology Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland
AU  - Curtis J
FAU - Curtis, JE
AD  - National Institute of Standards and Technology Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland
AU  - Kelman Z
FAU - Kelman, Z
AD  - Biochemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland
AD  - Institute for Bioscience and Biotechnology Research, Rockville, Maryland
TA  - Biophys J
JT  - Biophysical Journal
SO  - Biophys J. 2011 Dec 21;101(12):2999-3007. doi:10.1016/j.bpj.2011.11.006.