Abstract
Arthropod hemocyanins are large respiratory proteins that are composed of up to 48 subunits (8 × 6-mer) in the 75 kDa range. A 3D reconstruction of the 1 × 6-mer hemocyanin from the European spiny lobster Palinurus elephas has been performed from 9970 single particles using cryoelectron microscopy. An 8 Å resolution of the hemocyanin 3D reconstruction has been obtained from about 600 final class averages. Visualisation of structural elements such as α-helices has been achieved. An amino acid sequence alignment shows the high sequence identity (>80%) of the hemocyanin subunits from the European spiny lobster P. elephas and the American spiny lobster Panulirus interruptus. Comparison of the P. elephas hemocyanin electron microscopy (EM) density map with the known P. interruptus X-ray structure shows a close structural correlation, demonstrating the reliability of both methods for reconstructing proteins. By molecular modelling, we have found the putative locations for the amino acid sequence (597-605) and the C-terminal end (654-657), which are absent in the available P. interruptus X-ray data.
| Original language | English |
|---|---|
| Journal | Journal of Molecular Biology |
| Volume | 325 |
| Issue number | 1 |
| Pages (from-to) | 99-109 |
| Number of pages | 11 |
| ISSN | 0022-2836 |
| DOIs | |
| Publication status | Published - 2003 |
Funding
We thank Jaap J. Beintema and Heinz Decker for the antibodies, Anne Hembach and Cornelia Milke for their help in performing the cDNA cloning, Michail Isupov and Alexei Vagin for the program MOLREP and Bruno Klaholz for introduction to “O” and the rigid-body-fit program, which were used for preliminary fitting studies. This work has been supported by grants from the DFG (Ma843/4-3, Bu956/3-5) and the Stiftung Innovation von Rheinland-Pfalz (GZ. 8312-386 261/281).
