title: Characterization of AMA, a new AAA protein from Archaeoglobus and methanogenic archaea.
abstract: 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 beta-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-DeltaN) domains. AfAMA forms hexameric complexes, as does AMA-N, while AMA-DeltaN 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.
authors.affiliation: Department of Protein Evolution, Max-Planck-Institute for Developmental Biology, Spemannstrasse 35, D-72076 Tübingen, Germany.
authors.forename: Sergej
authors.initials: S
authors.lastname: Djuranovic
authors.forename: Beate
authors.initials: B
authors.lastname: Rockel
authors.forename: Andrei N
authors.initials: AN
authors.lastname: Lupas
authors.forename: Jörg
authors.initials: J
authors.lastname: Martin
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001105:Archaea / Q000201:enzymology*; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D019609:Archaeoglobus / Q000201:enzymology*; D002942:Circular Dichroism; D003001:Cloning, Molecular; D004795:Enzyme Stability; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010802:Phylogeny; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013696:Temperature
chemical_list: D019843:Archaeal Proteins; D011994:Recombinant Proteins; D000251:Adenosine Triphosphatases