ToxT: Difference between revisions

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==Structural Features==

DNA-binding. ToxT belongs to a family of transcriptional regulators headed by and known as AraC.<ref name="structure">PMID: 20133655</ref> The AraC family is characterized by a 100 amino acid region of sequence similarity that forms a <scene name='ToxT_Transcriptional_Regulator_in_Vibrio_cholerae/Two_hth_domains/1'>DNA-binding domain</scene> with two helix-turn-helix motifs (one on either side of the black linker). <ref name="arac">PMID: 11282467</ref> The two HTH regions are linked by a very polar alpha helix (shown in black). The overall domain is located at the C-terminus.<ref name="structure">PMID: 20133655</ref> Assuming ToxT is similar in mechanism to other AraC proteins, helix six from HTH1 and helix nine from HTH2 become aligned with the help of helix seven (the polar linking region) to allow binding to major consecutive grooves of target DNA (specific promoters for virulence genes).<ref name="structure">PMID: 20133655</ref>[http://www.pnas.org/content/107/7/2860/F3.large.jpg]. The conformation of helix seven is dependent on the ligand bound.

DNA-binding. ToxT belongs to a family of transcriptional regulators headed by and known as AraC.<ref name="structure">PMID: 20133655</ref> The AraC family is characterized by a 100 amino acid region of sequence similarity that forms a <scene name='ToxT_Transcriptional_Regulator_in_Vibrio_cholerae/Two_hth_domains/1'>DNA-binding domain</scene> with two helix-turn-helix motifs (one on either side of the black linker). <ref name="arac">PMID: 11282467</ref> This DNA binding domain is composed of seven alpha helices. HTH1 is composed of alpha helices five and six, while HTH2 is composed of alpha helices eight and nine. The two HTH regions are linked by the very polar alpha helix seven(shown in black). The overall domain is located at the C-terminus.<ref name="structure">PMID: 20133655</ref> Assuming ToxT is similar in mechanism to other AraC proteins, helix six from HTH1 and helix nine from HTH2 become aligned with the help of helix seven. Helix seven is positioned to attach to the N terminal binding pocket(the polar linking region) to allow binding to major consecutive grooves of target DNA (specific promoters for virulence genes).<ref name="structure">PMID: 20133655</ref>[http://www.pnas.org/content/107/7/2860/F3.large.jpg]. The conformation of helix seven is dependent on the ligand bound.

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 <StructureSection load='3gbg' color='structure' size='500' frame='true' align='right' caption='ToxT complex with palmitoleic acid, 1.9 Angstrom resolution crystal structure, [[3gbg]]' >
 ==Structural Features==
-<u>DNA-binding</u>. ToxT belongs to a family of transcriptional regulators headed by and known as AraC.<ref name="structure">PMID: 20133655</ref> The AraC family is characterized by a 100 amino acid region of sequence similarity that forms a <scene name='ToxT_Transcriptional_Regulator_in_Vibrio_cholerae/Two_hth_domains/1'>DNA-binding domain</scene> with two helix-turn-helix motifs (one on either side of the black linker). <ref name="arac">PMID: 11282467</ref> The two HTH regions are linked by a very polar alpha helix (shown in black). The overall domain is located at the C-terminus.<ref name="structure">PMID: 20133655</ref> Assuming ToxT is similar in mechanism to other AraC proteins, helix six from HTH1 and helix nine from HTH2 become aligned with the help of helix seven (the polar linking region) to allow binding to major consecutive grooves of target DNA (specific promoters for virulence genes).<ref name="structure">PMID: 20133655</ref>[http://www.pnas.org/content/107/7/2860/F3.large.jpg]. The conformation of helix seven is dependent on the ligand bound.
+<u>DNA-binding</u>. ToxT belongs to a family of transcriptional regulators headed by and known as AraC.<ref name="structure">PMID: 20133655</ref> The AraC family is characterized by a 100 amino acid region of sequence similarity that forms a <scene name='ToxT_Transcriptional_Regulator_in_Vibrio_cholerae/Two_hth_domains/1'>DNA-binding domain</scene> with two helix-turn-helix motifs (one on either side of the black linker). <ref name="arac">PMID: 11282467</ref> This DNA binding domain is composed of seven alpha helices. HTH1 is composed of alpha helices five and six, while HTH2 is composed of alpha helices eight and nine. The two HTH regions are linked by the very polar alpha helix seven(shown in black). The overall domain is located at the C-terminus.<ref name="structure">PMID: 20133655</ref> Assuming ToxT is similar in mechanism to other AraC proteins, helix six from HTH1 and helix nine from HTH2 become aligned with the help of helix seven. Helix seven is positioned to attach to the N terminal binding pocket(the polar linking region) to allow binding to major consecutive grooves of target DNA (specific promoters for virulence genes).<ref name="structure">PMID: 20133655</ref>[http://www.pnas.org/content/107/7/2860/F3.large.jpg]. The conformation of helix seven is dependent on the ligand bound.
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