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Publication Abstract from PubMed

Fidgetin like-1 protein (FIGL-1) is a homolog of fidgetin, a protein whose mutation leads to multiple developmental defects. FIGL-1 protein contains an AAA (ATPase associated with various activities) domain, and belongs to the AAA superfamily. However, the biological functions and developmental implications of this protein remain unknown. Here, we show that the AAA domain of the C. elegans FIGL-1 protein (CeFIGL-1-AAA), in clear contrast to homologous AAA domains, has an unusually high ATPase activity and forms a hexamer in solution. By determining the crystal structure of CeFIGL-1-AAA, we found that the loop linking helices alpha9 and alpha10 folds into a short helix alpha9a, which has an acidic surface and interacts with a positively-charged surface of neighboring subunit. Disruption of this charge interaction by mutagenesis diminishes both the ATPase activity and the oligomerization capacity of the protein. Interestingly, the acidic residues in alpha9a of CeFIGL-1-AAA are not conserved in other homologous AAA domains that have relatively low ATPase activities. These results demonstrate that the sequence of CeFIGL-1-AAA has adapted to establish an intersubunit charge interaction, which contributes to its strong oligomerization and ATPase activity. These unique properties of CeFIGL-1-AAA distinguish it from other homologous proteins, suggesting that CeFIGL-1 may have a distinct biological function.

Structural insights into unusually strong ATPase activity of the AAA domain of C. elegans fidgetin like-1 protein.,Peng W, Lin Z, Li W, Lu J, Shen Y, Wang C J Biol Chem. 2013 Aug 26. PMID:23979136^[2]

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