Narrowing the conformational space sampled by two-domain proteins with paramagnetic probes in both domains

作者：Dasgupta Soumyasri; Hu Xiaoyu; Keizers Peter H J; Liu Wei Min; Luchinat Claudio^*; Nagulapalli Malini; Overhand Mark; Parigi Giacomo; Sgheri Luca; Ubbink Marcellus

来源：Journal of Biomolecular NMR, 2011, 51(3): 253-263.

DOI：10.1007/s10858-011-9532-2

• Conformational heterogeneity
• Maximum allowed probability
• Maximum occurrence
• Paramagnetic proteins
• Paramagnetic tag
• Calmodulin

Calmodulin is a two-domain protein which in solution can adopt a variety of conformations upon reorientation of its domains. The maximum occurrence (MO) of a set of calmodulin conformations that are representative of the overall conformational space possibly sampled by the protein, has been calculated from the paramagnetism-based restraints. These restraints were measured after inclusion of a lanthanide binding tag in the C-terminal domain to supplement the data obtained by substitution of three paramagnetic lanthanide ions to the calcium ion in the second calcium binding loop of the N-terminal domain. The analysis shows that the availability of paramagnetic restraints arising from metal ions placed on both domains, reduces the MO of the conformations to different extents, thereby helping to identify those conformations that can be mostly sampled by the protein.

• 出版日期2011-11