High-Definition Dynein

The first atomic-resolution X-ray structure has been obtained for dynein, a motor protein that cruises around cells on microtubule tracks to pull apart DNA during cell division, ferry organelles and vesicles around cells, and drive the motions of flagella and cilia. A Japanese research team led by Osaka University’s Takahide Kon solved the massive protein’s structure at 2.8-Å resolution (shown; Nature, DOI: 10.1038/nature10955). Of the three molecular motors known to walk around cells on protein tracks, dynein has been the most elusive to crystallize. Structures of the other motor proteins, myosin and kinesin, were more easily solved—their motor domains are one-tenth of the size of dynein’s. “It has been a very intense and exciting year for dynein structures,” says Andrew P. Carter, a structural biologist at MRC Laboratory of Molecular Biology, in Cambridge, England. Last year, Carter’s group provided the first 6-Å glimpse of dynein (Science, DOI: 10.1126/science.1202393). That achievement was quickly followed by a 4.5-Å structure from Kon’s group, and just this month a 3.3-Å version from Carter’s group (Nat. Struct. Mol. Biol., DOI: 10.1038/nsmb.2074 and DOI: 10.1038/nsmb.2272). The new 2.8-Å and 3.3-Å structures “are going to provide a field day for all those who are interested in how motors work,” Carter says.