TAL effector: Difference between revisions

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Occurs seven times in PthXo1, and displays an unusual contact pattern to adenosine or cytosine bases. The aliphatic side chain of the isoleucine residue is observed to make non-polar van der Waals contacts to C8 (and N7) of the adenine purine ring, or to C5 of the cytosine pyrimidine ring.

N-terminal to the canonical repeats, the PthXo1 structure reveals two degenerate repeat folds that appear to cooperate to specify the conserved thymine that precedes the RVD-specified sequence (Figure 4). We have designated these as the 0th and -1st repeats. Residues 221 to 239 and residues 256 to 273 each form a helix and an adjoining loop that resembles helix 1 and the RVD loop in the canonical repeats; the remaining residues in each region are poorly ordered. Those two N-terminal regions converge near the 5′ thymine base, with the indole ring of tryptophan 232 (in the -1st repeat) making a van der Waals contact with the methyl group of that base. Mutation of the thymine reduces TAL effector activity at the target (3, 15). Tryptophan 232, as well as the surrounding residues, is highly conserved across available, intact TAL effector sequences.

TAL effector: Difference between revisions

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Revision as of 11:04, 3 January 2013 view source Philipp Warmer (talk \| contribs) 100 edits No edit summary ← Older edit		Revision as of 11:05, 3 January 2013 view source Philipp Warmer (talk \| contribs) 100 edits No edit summary Newer edit →
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	Occurs seven times in PthXo1, and displays an unusual contact pattern to adenosine or cytosine bases. The aliphatic side chain of the isoleucine residue is observed to make non-polar van der Waals contacts to C8 (and N7) of the adenine purine ring, or to C5 of the cytosine pyrimidine ring.		Occurs seven times in PthXo1, and displays an unusual contact pattern to adenosine or cytosine bases. The aliphatic side chain of the isoleucine residue is observed to make non-polar van der Waals contacts to C8 (and N7) of the adenine purine ring, or to C5 of the cytosine pyrimidine ring.


	N-terminal to the canonical repeats, the PthXo1 structure reveals two degenerate repeat folds that appear to cooperate to specify the conserved thymine that precedes the RVD-specified sequence (Figure 4). We have designated these as the 0th and -1st repeats. Residues 221 to 239 and residues 256 to 273 each form a helix and an adjoining loop that resembles helix 1 and the RVD loop in the canonical repeats; the remaining residues in each region are poorly ordered. Those two N-terminal regions converge near the 5′ thymine base, with the indole ring of tryptophan 232 (in the -1st repeat) making a van der Waals contact with the methyl group of that base. Mutation of the thymine reduces TAL effector activity at the target (3, 15). Tryptophan 232, as well as the surrounding residues, is highly conserved across available, intact TAL effector sequences.		N-terminal to the canonical repeats, the PthXo1 structure reveals two degenerate repeat folds that appear to cooperate to specify the conserved thymine that precedes the RVD-specified sequence (Figure 4). We have designated these as the 0th and -1st repeats. Residues 221 to 239 and residues 256 to 273 each form a helix and an adjoining loop that resembles helix 1 and the RVD loop in the canonical repeats; the remaining residues in each region are poorly ordered. Those two N-terminal regions converge near the 5′ thymine base, with the indole ring of tryptophan 232 (in the -1st repeat) making a van der Waals contact with the methyl group of that base. Mutation of the thymine reduces TAL effector activity at the target (3, 15). Tryptophan 232, as well as the surrounding residues, is highly conserved across available, intact TAL effector sequences.