Characterization of AMA, a new AAA protein from Archaeoglobus and methanogenic archaea

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• 作者：Sergej Djuranovic ; Beate Rockel ; Andrei N. Lupas and Jö ; rg Martin
• 刊名：Journal of Structural Biology
• 出版年：2006
• 出版时间：October 2006
• 年：2006
• 卷：156
• 期：1
• 页码：130-138
• 全文大小：2672 K

文摘

We have previously reported a new group of AAA proteins, which is only found in Archaeoglobus and methanogenic archaea (AMA). The proteins are phylogenetically basal to the metalloprotease clade and their N-terminal domain is homologous to the β-clam part of the N-domain of CDC48-like proteins. Here we report the biochemical and biophysical characterization of Archaeoglobus fulgidus AMA, and of its isolated N-terminal (AMA-N) and ATPase (AMA-ΔN) domains. AfAMA forms hexameric complexes, as does AMA-N, while AMA-ΔN only forms dimers. The ability to hexamerize is dependent on the integrity of a GYPL motif in AMA-N, which resembles the pore motif of FtsH and HslU. While the physiological function of AMA is unknown, we show that it has ATP-dependent chaperone activity and can prevent the thermal aggregation of proteins in vitro. The ability to interact with non-native proteins resides in the N-domain and is energy-independent.