Structure of the archaeal pab87 peptidase reveals a novel self-compartmentalizing protease family.
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.
Delfosse
Vanessa
V
Centre de Recherche des Cordeliers, LRMA, INSERM UMR-S 872, Université Pierre et Marie Curie, Paris, France.
Girard
Eric
E
Birck
Catherine
C
Delmarcelle
Michaël
M
Delarue
Marc
M
Poch
Olivier
O
Schultz
Patrick
P
Mayer
Claudine
C
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
D010455:Peptides; D010447:Peptide Hydrolases