title: Reciprocal influence of protein domains in the cold-adapted acyl aminoacyl peptidase from Sporosarcina psychrophila.
abstract: Acyl aminoacyl peptidases are two-domain proteins composed by a C-terminal catalytic α/β-hydrolase domain and by an N-terminal β-propeller domain connected through a structural element that is at the N-terminus in sequence but participates in the 3D structure of the C-domain. We investigated about the structural and functional interplay between the two domains and the bridge structure (in this case a single helix named α1-helix) in the cold-adapted enzyme from Sporosarcina psychrophila (SpAAP) using both protein variants in which entire domains were deleted and proteins carrying substitutions in the α1-helix. We found that in this enzyme the inter-domain connection dramatically affects the stability of both the whole enzyme and the β-propeller. The α1-helix is required for the stability of the intact protein, as in other enzymes of the same family; however in this psychrophilic enzyme only, it destabilizes the isolated β-propeller. A single charged residue (E10) in the α1-helix plays a major role for the stability of the whole structure. Overall, a strict interaction of the SpAAP domains seems to be mandatory for the preservation of their reciprocal structural integrity and may witness their co-evolution.
authors: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.
authors: Federica
authors: F
authors: Parravicini
authors: Antonino
authors: A
authors: Natalello
authors: Elena
authors: E
authors: Papaleo
authors: Luca
authors: L
authors: De Gioia
authors: Silvia Maria
authors: SM
authors: Doglia
authors: Marina
authors: M
authors: Lotti
authors: Stefania
authors: S
authors: Brocca
mesh_terms: D000222:Adaptation, Physiological; D020134:Catalytic Domain; D003001:Cloning, Molecular; D003080:Cold Temperature; D004795:Enzyme Stability; D056004:Molecular Dynamics Simulation; D016296:Mutagenesis; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D017384:Sequence Deletion; D012995:Solubility; D058644:Sporosarcina / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*
chemical_list: D011994:Recombinant Proteins; D010447:Peptide Hydrolases; C038220:acylaminoacyl-peptidase