6r83

Publication Abstract from PubMed

The oxygen transporter of molluscs, hemocyanin, consists of long pearl-necklace-like subunits of several globular domains. The subunits assemble in a complex manner to form cylindrical decamers. Typically, the first six domains of each subunit assemble together to form the cylinder wall, while the C-terminal domains form a collar that fills or caps the cylinder. During evolution, various molluscs have been able to fine-tune their oxygen binding by deleting or adding C-terminal domains and adjusting their inner-collar architecture. However, squids have duplicated one of the wall domains of their subunits instead. Here, using cryo-EM and an optimized refinement protocol implemented in SPHIRE, this work tackled the symmetry-mismatched structure of squid hemocyanin, revealing the precise effect of this duplication on its quaternary structure and providing a potential model for its structural evolution.

Cryo-EM reveals the asymmetric assembly of squid hemocyanin.,Tanaka Y, Kato S, Stabrin M, Raunser S, Matsui T, Gatsogiannis C IUCrJ. 2019 Apr 5;6(Pt 3):426-437. doi: 10.1107/S205225251900321X. eCollection, 2019 May 1. PMID:31098023^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.