#1: Journal: J Biol Chem / Year: 2006 Title: An archaeal peptidase assembles into two different quaternary structures: A tetrahedron and a giant octahedron. Authors: Guy Schoehn / Frédéric M D Vellieux / M Asunción Durá / Véronique Receveur-Bréchot / Céline M S Fabry / Rob W H Ruigrok / Christine Ebel / Alain Roussel / Bruno Franzetti / Abstract: Cellular proteolysis involves large oligomeric peptidases that play key roles in the regulation of many cellular processes. The cobalt-activated peptidase TET1 from the hyperthermophilic Archaea ...Cellular proteolysis involves large oligomeric peptidases that play key roles in the regulation of many cellular processes. The cobalt-activated peptidase TET1 from the hyperthermophilic Archaea Pyrococcus horikoshii (PhTET1) was found to assemble as a 12-subunit tetrahedron and as a 24-subunit octahedral particle. Both quaternary structures were solved by combining x-ray crystallography and cryoelectron microscopy data. The internal organization of the PhTET1 particles reveals highly self-compartmentalized systems made of networks of access channels extended by vast catalytic chambers. The two edifices display aminopeptidase activity, and their organizations indicate substrate navigation mechanisms different from those described in other large peptidase complexes. Compared with the tetrahedron, the octahedron forms a more expanded hollow structure, representing a new type of giant peptidase complex. PhTET1 assembles into two different quaternary structures because of quasi-equivalent contacts that previously have only been identified in viral capsids.
SHEET DETERMINATION METHOD: DSSP THE SHEETS PRESENTED AS "BB" IN EACH CHAIN ON SHEET RECORDS BELOW ... SHEET DETERMINATION METHOD: DSSP THE SHEETS PRESENTED AS "BB" IN EACH CHAIN ON SHEET RECORDS BELOW IS ACTUALLY AN 6-STRANDED BARREL THIS IS REPRESENTED BY A 7-STRANDED SHEET IN WHICH THE FIRST AND LAST STRANDS ARE IDENTICAL. THE SHEETS PRESENTED AS "GB" IN EACH CHAIN ON SHEET RECORDS BELOW IS ACTUALLY AN 6-STRANDED BARREL THIS IS REPRESENTED BY A 7-STRANDED SHEET IN WHICH THE FIRST AND LAST STRANDS ARE IDENTICAL.
Mass: 18.015 Da / Num. of mol.: 1506 / Source method: isolated from a natural source / Formula: H2O
Has protein modification
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Experimental details
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Experiment
Experiment
Method: X-RAY DIFFRACTION / Number of used crystals: 1
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Sample preparation
Crystal
Density Matthews: 2.97 Å3/Da / Density % sol: 59 % / Description: NONE
Crystal grow
Method: vapor diffusion, hanging drop / pH: 7.5 Details: HANGING DROP. MOTHER LIQUOR: 1 ML OF 0.1 M TRIS-HCL, PH 7.5, 20% (W/V) PEG 3350, 0.2 M TRIMETHYLAMINE N-OXIDE. DROP: 2 UL OF MOTHER LIQUOR PLUS 2 UL OF A 6.2 MG/ML PROTEIN SOLUTION IN 20 MM ...Details: HANGING DROP. MOTHER LIQUOR: 1 ML OF 0.1 M TRIS-HCL, PH 7.5, 20% (W/V) PEG 3350, 0.2 M TRIMETHYLAMINE N-OXIDE. DROP: 2 UL OF MOTHER LIQUOR PLUS 2 UL OF A 6.2 MG/ML PROTEIN SOLUTION IN 20 MM TRIS-HCL, 150 MM NACL, PH 7.5. CRYSTALS AFTER 2 WEEKS. CRYOPROTECTING SOLUTION: 0.1 M TRIS-HCL, PH 7.5, 20% (W/V) PEG 3350, 0.2 M TRIMETHYLAMINE N-OXIDE, 20% (V/V) ETHYLENE GLYCOL