1H, 15N and 13C resonance assignment of the pair of Factor-I like modules of the complement protein C7

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Updated: Jun 21, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
14:55

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy

Published on: September 17, 2017

Marie M Phelan1, Chuong-Thu Thai, Andrew P Herbert

  • 1Edinburgh Biomolecular NMR Unit, Joseph Black Building, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, Scotland, UK. marie.phelan@ed.ac.uk

Biomolecular NMR Assignments
|July 29, 2009
PubMed

Insights

Researchers characterized the human complement component C7 carboxy terminus (C7-FIMs), crucial for the innate immune system's Membrane Attack Complex. This study achieved 93% of the protein's (1)H, (15)N, and (13)C assignment using NMR spectroscopy.

Area of Science:

  • Biochemistry
  • Immunology
  • Structural Biology

Background:

  • The carboxy terminus of human complement component C7 contains two Factor I-like Modules (FIMs).
  • These FIMs are critical for the assembly of the Membrane Attack Complex (MAC), a key component of the innate immune system's terminal pathway.

Purpose of the Study:

  • To characterize the structure of the recombinant C7-FIMs protein, encompassing the C-terminal domain of human complement component C7.
  • To achieve a comprehensive assignment of the protein's nuclear magnetic resonance (NMR) spectral data.

Main Methods:

  • Recombinant expression of the C7-FIMs protein (16.9 kDa).
  • Conventional triple resonance NMR experiments for (1)H, (15)N, and (13)C assignment.
  • Data deposition in the BioMagResBank (Accession No. 15996).

Main Results:

  • Achieved 93% assignment for (1)H, (15)N, and (13)C nuclei.
  • Identified unassigned regions corresponding to a flexible N-terminus and an undefined loop.
  • The protein is disulfide-rich, consistent with its structural domain.

Conclusions:

  • The study provides significant structural insights into the C7-FIMs domain, essential for MAC formation.
  • The high degree of assignment facilitates further structural and functional studies of this innate immunity component.
  • The deposited chemical shifts serve as a valuable resource for the scientific community.

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