Dynactins p25 and p27 are predicted to adopt the LβH fold

Dynactin is a multimeric protein essential for the minus-end-directed transport driven by microtubule-based motor dynein. The pointed-end subcomplex in dynactin contains p62, p27, p25, and Arp11 subunits, and is thought to participate in interactions with membranous cargoes. We used sequence and structure prediction analysis to study dynactins p25 and p27. Here we present evidence that strongly supports that dynactins p27 and p25 contain the isoleucine-patch motif and adopt the left-handed parallel beta-helix fold. The structural models we obtained could contribute to the understanding of the complex interactions that dynactins are able to establish with cargo particles, microtubules or other dynactin subunits. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.