3POR image
Deposition Date 1992-11-09
Release Date 1993-07-15
Last Version Date 2024-02-21
Entry Detail
PDB ID:
3POR
Keywords:
INTEGRAL MEMBRANE PROTEIN PORIN
Title:
PORIN CONFORMATION IN THE ABSENCE OF CALCIUM; REFINED STRUCTURE AT 2.5 ANGSTROMS RESOLUTION
Biological Source:
Source Organism(s):
Rhodobacter capsulatus (Taxon ID: 1061)
Method Details:
Experimental Method:
X-RAY DIFFRACTION
Resolution:
2.50 Å
R-Value Work:
0.18
Space Group:
H 3
3POR validation report missing
Macromolecular Entities
Structures with similar UniProt ID
Structural Superimposition Protein Blast
Polymer Type:polypeptide(L)
Molecule:PORIN
Chain IDs:A
Chain Length:301
Number of Molecules:1
Biological Source:Rhodobacter capsulatus
UniProt ID:P31243 Pfam ID:PF13609
Ligand Molecules
C8E
TRS
Primary Citation
Porin conformation in the absence of calcium. Refined structure at 2.5 A resolution.
J. Mol. Biol. 231 817 824 (1993)
PMID: 7685826 DOI: 10.1006/jmbi.1993.1328

Abstact

The crystal structure of porin from Rhodobacter capsulatus in the absence of divalent calcium ions has been refined to convergence at a resolution of 2.5 A using the simulated annealing refinement method. The final model consists of all 301 amino acid residues, 77 solvent molecules, one tris(hydroxymethyl)-aminomethane molecule and one unknown ligand modeled as n-octyltetraoxyethylene. A superposition with the previously described model containing three calcium ions showed structural changes at the segment 108-116 of the inner loop beta 5-beta 6, and at loops beta 8-beta 9 and beta 11-beta 12 at the extracellular side of the porin molecule. Evidence is presented that the conformational changes depend on the presence or absence of calcium ions. A possible influence on porin function is discussed.

Legend

Protein

Chemical

Disease

Primary Citation of related structures
3POR
Feedback Form
Name
Email
Institute
Feedback