title: Structure of the archaeal pab87 peptidase reveals a novel self-compartmentalizing protease family.
abstract: Self-compartmentalizing proteases orchestrate protein turnover through an original architecture characterized by a central catalytic chamber. Here we report the first structure of an archaeal member of a new self-compartmentalizing protease family forming a cubic-shaped octamer with D(4) symmetry and referred to as CubicO. We solved the structure of the Pyrococcus abyssi Pab87 protein at 2.2 A resolution using the anomalous signal of the high-phasing-power lanthanide derivative Lu-HPDO3A. A 20 A wide channel runs through this supramolecular assembly of 0.4 MDa, giving access to a 60 A wide central chamber holding the eight active sites. Surprisingly, activity assays revealed that Pab87 degrades specifically d-amino acid containing peptides, which have never been observed in archaea. Genomic context of the Pab87 gene showed that it is surrounded by genes involved in the amino acid/peptide transport or metabolism. We propose that CubicO proteases are involved in the processing of d-peptides from environmental origins.
authors.affiliation: Centre de Recherche des Cordeliers, LRMA, INSERM UMR-S 872, Université Pierre et Marie Curie, Paris, France.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Delfosse
authors.forename: Eric
authors.initials: E
authors.lastname: Girard
authors.forename: Catherine
authors.initials: C
authors.lastname: Birck
authors.forename: Michaël
authors.initials: M
authors.lastname: Delmarcelle
authors.forename: Marc
authors.initials: M
authors.lastname: Delarue
authors.forename: Olivier
authors.initials: O
authors.lastname: Poch
authors.forename: Patrick
authors.initials: P
authors.lastname: Schultz
authors.forename: Claudine
authors.initials: C
authors.lastname: Mayer
mesh_terms: D001105:Archaea; D018360:Crystallography, X-Ray; D010447:Peptide Hydrolases / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D011487:Protein Conformation; D043903:Pyrococcus abyssi / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D010455:Peptides; D010447:Peptide Hydrolases