6H6S

Sad phasing on nickel-substituted human carbonic anhydrase II


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.150 
  • R-Value Observed: 0.152 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Non-crystallographic symmetry in proteins: Jahn-Teller-like and Butterfly-like effects?

Silva, J.M.Giuntini, S.Cerofolini, L.Geraldes, C.F.G.C.Macedo, A.L.Ravera, E.Fragai, M.Luchinat, C.Calderone, V.

(2019) J Biol Inorg Chem 24: 91-101

  • DOI: 10.1007/s00775-018-1630-0
  • Primary Citation of Related Structures:  
    6H6S

  • PubMed Abstract: 
  • Partial symmetry, i.e., the presence of more than one molecule in the asymmetric unit of a crystal, is a relatively rare phenomenon in small-molecule crystallography, but is quite common in protein crystallography, where it is typically known as non-crystallographic symmetry (NCS) ...

    Partial symmetry, i.e., the presence of more than one molecule in the asymmetric unit of a crystal, is a relatively rare phenomenon in small-molecule crystallography, but is quite common in protein crystallography, where it is typically known as non-crystallographic symmetry (NCS). Several papers in literature propose molecular determinants such as crystal contacts, thermal factors, or TLS parameters as an explanation for the phenomenon of intrinsic asymmetry among molecules that are in principle equivalent. Nevertheless, are all of the above determinants the cause or are they rather the effect? In the general frame of the NCS often observed in crystals of biomolecules, this paper deals with nickel(II)-substituted human carbonic anhydrase(II) (hCAII) and its SAD structure determination at the nickel edge. The structure revealed two non-equivalent molecules in the asymmetric unit, the presence of a secondary nickel-binding site at the N-terminus of both molecules (which had never been found before in the nickel-substituted enzyme) and two different coordination geometries of the active site nickel (hexa-coordinated in one molecule and mainly penta-coordinated in the other). The above-mentioned standard molecular crystallographic determinants of this asymmetry are analyzed and presented in detail for this particular case. From these considerations, we speculate on the existence of a fundamental, although yet unknown, common cause for the partial symmetry that is so often encountered in X-ray structures of biomolecules.


    Organizational Affiliation

    Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, FI, Italy. calderone@cerm.unifi.it.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Carbonic anhydrase 2A, B259Homo sapiensMutation(s): 0 
Gene Names: CA2
EC: 4.2.1.1
Find proteins for P00918 (Homo sapiens)
Explore P00918 
Go to UniProtKB:  P00918
NIH Common Fund Data Resources
PHAROS:  P00918
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.150 
  • R-Value Observed: 0.152 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 73.48α = 90
b = 41.18β = 109.25
c = 84.04γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XSCALEdata scaling
autoSHARPphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-01-09
    Type: Initial release
  • Version 1.1: 2019-03-06
    Changes: Data collection, Database references
  • Version 1.2: 2019-08-21
    Changes: Data collection, Derived calculations
  • Version 1.3: 2019-11-20
    Changes: Derived calculations