Pyrococcus horikoshii TET2 Peptidase Assembling Process and Associated Functional Regulation

Abstract

Background: TET aminopeptidases are 12-subunit complexes present in the three domains of life and are involved in important biological functions. Results: The TET assembling process has been characterized. The oligomerization triggers TET activity toward large polypeptidic substrates. Conclusion:The assembling of TET is a controlled process and regulates its activity in vivo. Significance: This work provides a new example of peptidase regulation driven by self-oligomerization.

Small-angle neutron scattering reveals the assembly mode and oligomeric architecture of TET, a large, dodecameric aminopeptidase

“…S12). As a basic unit, dimeric building blocks were chosen (in agreement with previous SAXS data; Appolaire et al, 2013) and generated with the symmetry operator prior to generating the whole dodecameric model. In the case of PhTET3, addition of the N-terminal part (residues 1-7) as well as the internal loop (residues 128-136) led to a nonsatisfactory fit of the hPhTET3 12s SANS reference curve in 100% D 2 O. Consequently, the PhTET3 dimeric building bock was generated using a manual rigid body to slightly change the relative position of one monomer with respect to the second monomer within the dimeric building block.…”

“…PhTET homododecamers are very stable, even at high temperatures (90 C), a fact attributed to the properties of the dimer interfaces (Appolaire et al, 2013). In vivo studies, combined with small-angle X-ray scattering (SAXS), showed that dimers are the elementary building blocks and, based on electron microscopy (EM) and analytical ultracentrifugation (AUC) data, a working model with hexameric intermediates assembling into the final dodecameric edifices has been suggested (Appolaire et al, 2013).…”

“…Each TET subunit is formed by a proteolytic and a PDZ-like domain that mediate both the dimeric interface and the dimer-dimer interface that build the whole tetrahedral particle. We recently demonstrated that the activity of TET aminopeptidase towards long polypeptides is coupled with its assembly process (Appolaire et al, 2013;Rosenbaum et al, 2011): the co-occurrence in vivo of stable TET dimeric precursors and assembled dodecamers suggests that, at least in archaea, the TET oligopeptidase activity is regulated by control of its oligomerization state. PhTET homododecamers are very stable, even at high temperatures (90 C), a fact attributed to the properties of the dimer interfaces (Appolaire et al, 2013).…”

“…We recently demonstrated that the activity of TET aminopeptidase towards long polypeptides is coupled with its assembly process (Appolaire et al, 2013;Rosenbaum et al, 2011): the co-occurrence in vivo of stable TET dimeric precursors and assembled dodecamers suggests that, at least in archaea, the TET oligopeptidase activity is regulated by control of its oligomerization state. PhTET homododecamers are very stable, even at high temperatures (90 C), a fact attributed to the properties of the dimer interfaces (Appolaire et al, 2013). In vivo studies, combined with small-angle X-ray scattering (SAXS), showed that dimers are the elementary building blocks and, based on electron microscopy (EM) and analytical ultracentrifugation (AUC) data, a working model with hexameric intermediates assembling into the final dodecameric edifices has been suggested (Appolaire et al, 2013).…”

Heat-induced conformational changes of TET peptidase from crenarchaeon Desulfurococcus kamchatkensis

“…Numerous intracellular energy-independent peptidases coexist in the cytosol, but only a few of them share the capacity to self-assembly as large homomultimeric complexes. These include bleomycin hydrolase, leucine aminopeptidase, DppA, TPPII, TRI protease, protease1, pab87, and TET aminopeptidase (Appolaire et al 2013;Joshua-Tor et al 1995;Remaut et al 2001;Geier et al 1999;Brandstetter et al 2001). In Archaea, two giant exopeptidase systems have been identified: TRI (a hexameric ring assembly) and TET (a tetrahedrally shaped dodecameric complex) (Tamura et al 1996, Franzetti et al 2002.…”