X-ray structure of a human cardiac muscle troponin C/troponin I chimera in two crystal forms

Journal Article · 31 December 2021 · Acta Crystallographica. Section F, Structural Biology Communications

DOI: https://doi.org/10.1107/s2053230x21012395 · OSTI ID:1982860

Yan, Chunhong ^[1]; Sack, John S. ^[1]

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1. Bristol Myers Squibb Research and Development, Princeton, NJ (United States). Small Molecule Drug Discovery

The X-ray crystal structure of a human cardiac muscle troponin C/troponin I chimera has been determined in two different crystal forms and shows a conformation of the complex that differs from that previously observed by NMR. The chimera consists of the N-terminal domain of troponin C (cTnC; residues 1–80) fused to the switch region of troponin I (cTnI; residues 138–162). In both crystal forms, the cTnI residues form a six-turn α-helix that lays across the hydrophobic groove of an adjacent cTnC molecule in the crystal structure. In contrast to previous models, the cTnI helix runs in a parallel direction relative to the cTnC groove and completely blocks the calcium desensitizer binding site of the cTnC–cTnI interface.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS); Bristol Myers Squibb Research and Development, Princeton, NJ (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1982860
• Journal Information: Acta Crystallographica. Section F, Structural Biology Communications, Journal Name: Acta Crystallographica. Section F, Structural Biology Communications Journal Issue: 1 Vol. 78; ISSN ACSFEN; ISSN 2053-230X
• Publisher: International Union of CrystallographyCopyright Statement
• Country of Publication: United States
• Language: English