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

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


Abstract 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.

• Content Type Journal Article
• Pages 1-11
• DOI 10.1007/s10858-011-9532-2
• Authors
  • Soumyasri Dasgupta, Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
  • Xiaoyu Hu, Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
  • Peter H. J. Keizers, Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO box 9502, 2300 RA Leiden, Netherlands
  • Wei-Min Liu, Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO box 9502, 2300 RA Leiden, Netherlands
  • Claudio Luchinat, Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
  • Malini Nagulapalli, Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
  • Mark Overhand, Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO box 9502, 2300 RA Leiden, Netherlands
  • Giacomo Parigi, Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
  • Luca Sgheri, Istituto per le Applicazioni del Calcolo, Sezione di Firenze, CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
  • Marcellus Ubbink, Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO box 9502, 2300 RA Leiden, Netherlands

• • Journal Journal of Biomolecular NMR
  • Online ISSN 1573-5001
  • Print ISSN 0925-2738

Source: Journal of Biomolecular NMR