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ExbB
From Proteopedia
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| - | + | <StructureSection load='5zfu' size='350' side='right' caption='ExbB pentamer complex with ExbD peptide (red) (PDB code [[5zfu]])' scene=''> | |
| - | + | [[Image:ExbB.jpg|300px|right|thumb| The Structure of ExbB<ref name='Kampfenkel'>PMID: 8449962</ref>]] | |
| - | ExbB | + | |
== Structure== | == Structure== | ||
| - | [[ | + | '''ExbB''' consists of three transmembrane domains (spanning from residues 16-39, 128-155 and 162-194), with two large portions of the protein representing the majority of the protein in the cytoplasm and two smaller portions in the periplasm<ref name='Kampfenkel'>PMID: 8449962</ref>. |
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| + | ExbB can exist in the [[TonB]] system either in a complex with [[ExbD]] (to a ratio of 3.5:1) or on its own (where no ExbD is present), which has been suggested to play a part in the diverse roles of TonB<ref name='Held'>PMID: 12193634</ref>. | ||
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| + | ExbB has a similar sequence and physiological structure to [[TolQ]] and is therefore thought to be evolutionarily linked<ref name='Braun'>PMID: 15205446</ref>. | ||
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| + | ==Function== | ||
| + | ExbB is essential for TonB-dependent energy transduction as the absence of ExbB prevents TonB responding to the proton motive force, as well as the change of the high-affinity association of TonB for the outer membrane to the cytoplasmic membrane<ref name='Held'>PMID: 12193634</ref>. | ||
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| + | Loss of ExbB function can be partially replaced by TolQ and vice versa - reduced activities of either of these proteins via a mutant form can be reversed by introducing double mutants<ref name='Braun'>PMID: 15205446</ref>. | ||
| + | </StructureSection> | ||
| + | ==3D structures of ExbB== | ||
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| + | Updated on {{REVISIONDAY2}}-{{MONTHNAME|{{REVISIONMONTH}}}}-{{REVISIONYEAR}} | ||
| - | ExbB | + | [[5zfu]], [[5zfv]] – EcExbB + ExbD peptide – ''Escherichia coli'' – Cryo EM<br /> |
| + | [[6tyi]] – EcExbB + ExbD – Cryo EM<br /> | ||
| + | [[5sv1]] – ExbB + ExbD peptide <br /> | ||
| + | [[5sv0]], [[5zfp]] – EcExbB <br /> | ||
| + | [[6ye4]] – SmExbB – ''Serratia marsescens'' - Cryo EM<br /> | ||
| + | [[7ajq]] – SmExbB + ExbD - Cryo EM<br /> | ||
== References== | == References== | ||
<references/> | <references/> | ||
| + | [[Category:Topic Page]] | ||
Current revision
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3D structures of ExbB
Updated on 26-February-2023
5zfu, 5zfv – EcExbB + ExbD peptide – Escherichia coli – Cryo EM
6tyi – EcExbB + ExbD – Cryo EM
5sv1 – ExbB + ExbD peptide
5sv0, 5zfp – EcExbB
6ye4 – SmExbB – Serratia marsescens - Cryo EM
7ajq – SmExbB + ExbD - Cryo EM
References
- ↑ 1.0 1.1 Kampfenkel K, Braun V. Topology of the ExbB protein in the cytoplasmic membrane of Escherichia coli. J Biol Chem. 1993 Mar 15;268(8):6050-7. PMID:8449962
- ↑ 2.0 2.1 Held KG, Postle K. ExbB and ExbD do not function independently in TonB-dependent energy transduction. J Bacteriol. 2002 Sep;184(18):5170-3. PMID:12193634
- ↑ 3.0 3.1 Braun V, Herrmann C. Point mutations in transmembrane helices 2 and 3 of ExbB and TolQ affect their activities in Escherichia coli K-12. J Bacteriol. 2004 Jul;186(13):4402-6. PMID:15205446 doi:10.1128/JB.186.13.4402-4406.2004
