2X9K

Structure of a E.coli porin

Summary for 2X9K

• Entry DOI: 10.2210/pdb2x9k/pdb
• Related: 2F1C 2IWV 2IWW 2WVP
• Descriptor: OUTER MEMBRANE PROTEIN G, octyl beta-D-glucopyranoside (3 entities in total)
• Functional Keywords: transport protein, ion transport
• Biological source: ESCHERICHIA COLI
• Cellular location: Cell outer membrane; Multi-pass membrane protein: P76045
• Total number of polymer chains: 1
• Total formula weight: 35302.52

Authors

Korkmaz-Ozkan, F.,Koster, S.,Kuhlbrandt, W.,Mantele, W.,Yildiz, O. (deposition date: 2010-03-21, release date: 2011-01-26, Last modification date: 2024-05-08)

Primary citation

Korkmaz-Ozkan, F.,Koster, S.,Kuhlbrandt, W.,Mantele, W.,Yildiz, O.
Correlation between the Ompg Secondary Structure and its Ph-Dependent Alterations Monitored by Ftir.
J.Mol.Biol., 401:56-, 2010

PubMed Abstract: The channel activity of the outer-membrane protein G (OmpG) from Escherichia coli is pH-dependent. To investigate the role of the histidine pair His231/His261 in triggering channel opening and closing, we mutated both histidines to alanines and cysteines. Fourier transform infrared spectra revealed that the OmpG mutants stay-independent of pH-in an open conformation. Temperature ramp experiments indicate that the mutants are as stable as the open state of wild-type OmpG. The X-ray structure of the alanine-substituted OmpG mutant obtained at pH 6.5 confirms the constitutively open conformation. Compared to previous structures of the wild-type protein in the open and closed conformation, the mutant structure shows a difference in the extracellular loop L6 connecting beta-strands S12 and S13. A deletion of amino acids 220-228, which are thought to block the channel at low pH in wild-type OmpG, indicates conformational changes, which might be triggered by His231/His261.

PubMed: 20561532
DOI: 10.1016/J.JMB.2010.06.015

Experimental method

X-RAY DIFFRACTION (2.18 Å)