title: Quaternary structure of the European spiny lobster (Palinurus elephas) 1x6-mer hemocyanin from cryoEM and amino acid sequence data.
abstract: Arthropod hemocyanins are large respiratory proteins that are composed of up to 48 subunits (8 x 6-mer) in the 75kDa range. A 3D reconstruction of the 1 x 6-mer hemocyanin from the European spiny lobster Palinurus elephas has been performed from 9970 single particles using cryoelectron microscopy. An 8A resolution of the hemocyanin 3D reconstruction has been obtained from about 600 final class averages. Visualisation of structural elements such as alpha-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.
authors.affiliation: Institute of Zoology, University of Mainz, Muellerweg 6, D-55099 Mainz, Germany. u.meissner@uni-mainz.de
authors.forename: Ulrich
authors.initials: U
authors.lastname: Meissner
authors.forename: Michael
authors.initials: M
authors.lastname: Stohr
authors.forename: Kristina
authors.initials: K
authors.lastname: Kusche
authors.forename: Thorsten
authors.initials: T
authors.lastname: Burmester
authors.forename: Holger
authors.initials: H
authors.lastname: Stark
authors.forename: J Robin
authors.initials: JR
authors.lastname: Harris
authors.forename: Elena V
authors.initials: EV
authors.lastname: Orlova
authors.forename: Jürgen
authors.initials: J
authors.lastname: Markl
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D006433:Hemocyanins / Q000737:chemistry* / Q000648:ultrastructure*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D033521:Palinuridae / Q000737:chemistry*; D020836:Protein Structure, Quaternary; D021122:Protein Subunits; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D055672:Static Electricity
chemical_list: D021122:Protein Subunits; D006433:Hemocyanins