5al7
N-terminal fragment of Drosophila melanogaster Sas-6 (F143D), dimerised via the coiled-coil domain.N-terminal fragment of Drosophila melanogaster Sas-6 (F143D), dimerised via the coiled-coil domain.
Structural highlights
FunctionSAS6_DROME Central scaffolding component of the centrioles ensuring their 9-fold symmetry. Required for centrosome biogenesis and duplication.[1] [2] Publication Abstract from PubMedSas-6 and Ana2/STIL proteins are required for centriole duplication and the homo-oligomerisation properties of Sas-6 help establish the nine-fold symmetry of the central cartwheel that initiates centriole assembly. Ana2/STIL proteins are poorly conserved, but they all contain a predicted Central Coiled-Coil Domain (CCCD). Here we show that the Drosophila Ana2 CCCD forms a tetramer, and we solve its structure to 0.8 A, revealing that it adopts an unusual parallel-coil topology. We also solve the structure of the Drosophila Sas-6 N-terminal domain to 2.9 A revealing that it forms higher-order oligomers through canonical interactions. Point mutations that perturb Sas-6 or Ana2 homo-oligomerisation in vitro strongly perturb centriole assembly in vivo. Thus, efficient centriole duplication in flies requires the homo-oligomerisation of both Sas-6 and Ana2, and the Ana2 CCCD tetramer structure provides important information on how these proteins might cooperate to form a cartwheel structure. The homo-oligomerisation of both Sas-6 and Ana2 is required for efficient centriole assembly in flies.,Cottee MA, Muschalik N, Johnson S, Leveson J, Raff JW, Lea SM Elife. 2015 May 23;4. doi: 10.7554/eLife.07236. PMID:26002084[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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