6533b85dfe1ef96bd12be75c

RESEARCH PRODUCT

Structure of Mega-Hemocyanin Reveals Protein Origami in Snails

Christos GatsogiannisStefan RaunserJürgen MarklOliver Hofnagel

subject

Models MolecularProtein FoldingCryo-electron microscopymedicine.medical_treatmentGastropodaSnailsNanotechnologySnailBiologyMega-Cylinder (gastropod)Structural Biologybiology.animalHemolymphmedicineAnimalsProtein Structure QuaternaryMolecular BiologyCryoelectron MicroscopyProtein primary structureHemocyaninbiology.organism_classificationProtein SubunitsComplex proteinHemocyaninsBiophysicsProtein Multimerization

description

SummaryMega-hemocyanin is a 13.5 MDa oxygen transporter found in the hemolymph of some snails. Similar to typical gastropod hemocyanins, it is composed of 400 kDa building blocks but has additional 550 kDa subunits. Together, they form a large, completely filled cylinder. The structural basis for this highly complex protein packing is not known so far. Here, we report the electron cryomicroscopy (cryo-EM) structure of mega-hemocyanin complexes from two different snail species. The structures reveal that mega-hemocyanin is composed of flexible building blocks that differ in their conformation, but not in their primary structure. Like a protein origami, these flexible blocks are optimally packed, implementing different local symmetries and pseudosymmetries. A comparison between the two structures suggests a surprisingly simple evolutionary mechanism leading to these large oxygen transporters.

yearjournalcountryeditionlanguage
2014-07-01Structure
https://doi.org/10.1016/j.str.2014.10.013