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Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Cupredoxin-like domains in haemocyanins
Elmar Jaenicke1, Kay Büchler, Jürgen Markl
1Institut für Molekulare Biophysik, Johannes Gutenberg-Universität, Jakob Welder Weg 26, 55128 Mainz, Germany. elmar.jaenicke@uni-mainz.de
The Biochemical Journal
|December 23, 2009
Summary
Molluscan haemocyanins have a unique tail domain in functional unit H (FU-h) that is cupredoxin-like but copper-free. This structure suggests a role in copper uptake for oxygen-binding active sites in haemocyanins.
Area of Science:
- Biochemistry
- Structural Biology
- Molecular Evolution
Background:
- Haemocyanins are multimeric proteins that transport oxygen using type 3 copper sites.
- Molluscan haemocyanins feature large subunits composed of multiple functional units (FUs), including FU-h with a unique tail domain.
- Arthropod haemocyanin subunits also possess a domain reinterpreted as cupredoxin-like.
Purpose of the Study:
- To determine the structure of the tail domain of FU-h in keyhole limpet haemocyanin isoform 1 (KLH1).
- To investigate the presence of copper within this tail domain.
- To propose a functional and evolutionary role for cupredoxin-like domains in haemocyanins.
Main Methods:
- X-ray crystallography was employed to elucidate the three-dimensional structure of the KLH1 FU-h tail domain.
Main Results:
- The tail domain of KLH1 FU-h exhibits a cupredoxin-like structure.
- This domain was found to be devoid of copper.
- The copper-free domain 3 in arthropod haemocyanins is also structurally similar to cupredoxin.
Conclusions:
- The cupredoxin-like tail domain in molluscan FU-h and domain 3 in arthropod haemocyanins likely evolved from a common ancestor.
- We propose that these domains historically functioned in the transport and upload of copper to the haemocyanin active site.
- This finding provides insights into the evolutionary history and functional diversification of haemocyanins.
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