TolQ: Difference between revisions

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TolQ is a polytopic protein located in the inner (cytoplasmic) membrane. <ref>PMID: 8300535</ref> It contains approximately 230 amino acids and is important in the maintenance of the bacterial envelope integrity as well as the import of filamentous bacteriophage and group A colicins. <ref>PMID: ~~8300535~~</ref>

[[Image:TolQ.jpg|600px|right|thumb| The TolQ Membrane-spanning domains <ref>PMID: 8662905</ref>]]

==Structure==

There are three membrane spanning segments in TolQ. TM1 is connected to TM2 via a large cytoplasmic loop, with the N-terminal ending in the periplasm.

'''TolQ''' is a polytopic protein located in the inner (cytoplasmic) membrane, containing approximately 230 amino acids. There are three membrane spanning segments in TolQ with each segment containing an α-helix<ref>PMID: 7853390</ref>. TM1 is connected to TM2 via a large cytoplasmic loop, with the N-terminal ending in the periplasm. This topology is also found in [[ExbB]], which can be explained by the similar sequence shared by both proteins<ref name='Braun'>PMID: 15205446</ref>.

It has been shown that 4 to 6 TolQ molecules associate in the TolQRA complex, and that they form multimers which interact with the transmembrane helices (TMH) of TolQ, TolR and TolA <ref>PMID: 21285349</ref>. The multimers are formed by the three TMHs ~~<ref>PMID: 8300535</ref>~~ of TolQ, the last of which undergo a conformational change to form a hairpin, while the first TMH forms an intermolecular interaction

It has been shown that 4 to 6 TolQ molecules associate in the TolQRA complex, and that they form multimers which interact with the transmembrane helices (TMH) of TolQ, [[TolR]] and [[TolA]]<ref> PMID: 21285349</ref>. The multimers are formed by the three TMHs of TolQ, the last of which undergo a conformational change to form a hairpin, while the first TMH forms an intermolecular interaction<ref name='Vianney'> PMID:8300535</ref>.

==~~To view related Tol entries see:~~==

==Function==

TolQ plays an important role in the maintenance of the bacterial envelope integrity as well as the import of filamentous bacteriophage and group A colicins<ref name='Vianney'> PMID:8300535</ref>.

*[[Tol]]

Loss of TolQ function can be partially replaced by ExbB 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>.

*[[TolR]]

*[[TolA]]

*[[TolB]]

*[[Pal]]

*[[YbgF]]

*[[YbgC]]

== References==

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-TolQ is a polytopic protein located in the inner (cytoplasmic) membrane. <ref>PMID: 8300535</ref> It contains approximately 230 amino acids and is important in the maintenance of the bacterial envelope integrity as well as the import of filamentous bacteriophage and group A colicins. <ref>PMID: 8300535</ref>
+[[Image:TolQ.jpg|600px|right|thumb| The TolQ Membrane-spanning domains <ref>PMID: 8662905</ref>]]
 ==Structure==
-There are three membrane spanning segments in TolQ.  TM1 is connected to TM2 via a large cytoplasmic loop, with the N-terminal ending in the periplasm.
+'''TolQ''' is a polytopic protein located in the inner (cytoplasmic) membrane, containing approximately 230 amino acids.  There are three membrane spanning segments in TolQ with each segment containing an α-helix<ref>PMID: 7853390</ref>.  TM1 is connected to TM2 via a large cytoplasmic loop, with the N-terminal ending in the periplasm.  This topology is also found in [[ExbB]], which can be explained by the similar sequence shared by both proteins<ref name='Braun'>PMID: 15205446</ref>.
-It has been shown that 4 to 6 TolQ molecules associate in the TolQRA complex, and that they form multimers which interact with the transmembrane helices (TMH) of TolQ, TolR and TolA <ref>PMID: 21285349</ref>.   The multimers are formed by the three TMHs <ref>PMID: 8300535</ref> of TolQ, the last of which undergo a conformational change to form a hairpin, while the first TMH forms an intermolecular interaction
+It has been shown that 4 to 6 TolQ molecules associate in the TolQRA complex, and that they form multimers which interact with the transmembrane helices (TMH) of TolQ, [[TolR]] and [[TolA]]<ref> PMID: 21285349</ref>.  The multimers are formed by the three TMHs of TolQ, the last of which undergo a conformational change to form a hairpin, while the first TMH forms an intermolecular interaction<ref name='Vianney'> PMID:8300535</ref>.
-==To view related Tol entries see:==
+==Function==
+TolQ plays an important role in the maintenance of the bacterial envelope integrity as well as the import of filamentous bacteriophage and group A colicins<ref name='Vianney'> PMID:8300535</ref>.
-*[[Tol]]
+Loss of TolQ function can be partially replaced by ExbB 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>.
-*[[TolR]]
-*[[TolA]]
-*[[TolB]]
-*[[Pal]]
-*[[YbgF]]
-*[[YbgC]]
 == References==
 <references/>