4RL8 image
Deposition Date 2014-10-16
Release Date 2015-07-29
Last Version Date 2024-02-28
Entry Detail
PDB ID:
4RL8
Title:
Crystal structure of the COG4313 outer membrane channel from Pseudomonas putida F1
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.30 Å
R-Value Free:
0.25
R-Value Work:
0.21
R-Value Observed:
0.21
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Protein involved in meta-pathway of phenol degradation-like protein
Gene (Uniprot):Pput_2725
Chain IDs:A, B, C, D
Chain Length:275
Number of Molecules:4
Biological Source:Pseudomonas putida
Primary Citation
Crystal structure of a COG4313 outer membrane channel.
Sci Rep 5 11927 11927 (2015)
PMID: 26149193 DOI: 10.1038/srep11927

Abstact

COG4313 proteins form a large and widespread family of outer membrane channels and have been implicated in the uptake of a variety of hydrophobic molecules. Structure-function studies of this protein family have so far been hampered by a lack of structural information. Here we present the X-ray crystal structure of Pput2725 from the biodegrader Pseudomonas putida F1, a COG4313 channel of unknown function, using data to 2.3 Å resolution. The structure shows a 12-stranded barrel with an N-terminal segment preceding the first β-strand occluding the lumen of the barrel. Single channel electrophysiology and liposome swelling experiments suggest that while the narrow channel visible in the crystal structure does allow passage of ions and certain small molecules in vitro, Pput2725 is unlikely to function as a channel for hydrophilic molecules. Instead, the presence of bound detergent molecules inside the barrel suggests that Pput2725 mediates uptake of hydrophobic molecules. Sequence alignments and the locations of highly conserved residues suggest the presence of a dynamic lateral opening through which hydrophobic molecules might gain entry into the cell. Our results provide the basis for structure-function studies of COG4313 family members with known function, such as the SphA sphingosine uptake channel of Pseudomonas aeruginosa.

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