5L8S

The crystal structure of a cold-adapted acylaminoacyl peptidase reveals a novel quaternary architecture based on the arm-exchange mechanism


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.212 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

A bacterial acyl aminoacyl peptidase couples flexibility and stability as a result of cold adaptation.

Brocca, S.Ferrari, C.Barbiroli, A.Pesce, A.Lotti, M.Nardini, M.

(2016) FEBS J. 283: 4310-4324

  • DOI: 10.1111/febs.13925

  • PubMed Abstract: 
  • Life in cold environments requires an overall increase in the flexibility of macromolecular and supramolecular structures to allow biological processes to take place at low temperature. Conformational flexibility supports high catalytic rates of enzy ...

    Life in cold environments requires an overall increase in the flexibility of macromolecular and supramolecular structures to allow biological processes to take place at low temperature. Conformational flexibility supports high catalytic rates of enzymes in the cold but in several cases is also a cause of instability. The three-dimensional structure of the psychrophilic acyl aminoacyl peptidase from Sporosarcina psychrophila (SpAAP) reported in this paper highlights adaptive molecular changes resulting in a fine-tuned trade-off between flexibility and stability. In its functional form SpAAP is a dimer, and an increase in flexibility is achieved through loosening of intersubunit hydrophobic interactions. The release of subunits from the quaternary structure is hindered by an 'arm exchange' mechanism, in which a tiny structural element at the N terminus of one subunit inserts into the other subunit. Mutants lacking the 'arm' are monomeric, inactive and highly prone to aggregation. Another feature of SpAAP cold adaptation is the enlargement of the tunnel connecting the exterior of the protein with the active site. Such a wide channel might compensate for the reduced molecular motions occurring in the cold and allow easy and direct access of substrates to the catalytic site, rendering transient movements between domains unnecessary. Thus, cold-adapted SpAAP has developed a molecular strategy unique within this group of proteins: it is able to enhance the flexibility of each functional unit while still preserving sufficient stability.


    Organizational Affiliation

    Department of Biotechnology and Biosciences, University of Milano-Bicocca, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Amino acyl peptidase
A, B, C, D
604Sporosarcina psychrophilaMutation(s): 0 
Gene Names: aph
Find proteins for E1VFE0 (Sporosarcina psychrophila)
Go to UniProtKB:  E1VFE0
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.212 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 148.080α = 90.00
b = 151.100β = 90.00
c = 191.230γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
SCALAdata scaling
PHASERphasing
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Fondo di Ateneo of the University of Milano-Milano BicoccaItaly--

Revision History 

  • Version 1.0: 2016-11-16
    Type: Initial release
  • Version 1.1: 2016-12-14
    Type: Database references