Sandbox Reserved 1845: Difference between revisions
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=== F243 === | === F243 === | ||
<scene name='10/1075247/ | <scene name='10/1075247/Better_f234/1'>F243</scene> | ||
<scene name='10/1075247/I243/3'>F243I</scene> | <scene name='10/1075247/I243/3'>F243I</scene> | ||
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The original side chain at position 243 is phenylalanine, which is located 3.6 Å from the ligand. Two mutations at this position—F243I (isoleucine) and F243W (tryptophan)—increase the catalytic activity of the enzyme. The F243I mutation replaces phenylalanine with isoleucine, a smaller side chain that allows the ligand to sit closer. This reduces the ligand distance to 3.0 Å. This tighter interaction likely improves substrate binding. The F243W mutation introduces tryptophan, which has a bulkier, nitrogen-containing aromatic side chain. Tryptophan brings the ligand slightly closer at 3.2 Å and introduces potential for new interactions, such as hydrogen bonding or π-stacking. Both mutations result in improved catalytic performance. The F243I mutation leads to a 27.5% increase in activity, while the F243W mutation results in a 17.5% increase, compared to the wild-type enzyme. | The original side chain at position 243 is phenylalanine, which is located 3.6 Å from the ligand. Two mutations at this position—F243I (isoleucine) and F243W (tryptophan)—increase the catalytic activity of the enzyme. The F243I mutation replaces phenylalanine with isoleucine, a smaller side chain that allows the ligand to sit closer. This reduces the ligand distance to 3.0 Å. This tighter interaction likely improves substrate binding. The F243W mutation introduces tryptophan, which has a bulkier, nitrogen-containing aromatic side chain. Tryptophan brings the ligand slightly closer at 3.2 Å and introduces potential for new interactions, such as hydrogen bonding or π-stacking. Both mutations result in improved catalytic performance. The F243I mutation leads to a 27.5% increase in activity, while the F243W mutation results in a 17.5% increase, compared to the wild-type enzyme. | ||
=== Y127 === | === Y127 === | ||
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The mutation of tyrosine to glycine at position 127 (Y127G) also increases the protein's thermostability. The mutant melting point is increased to 87.0°C. Tyrosine has a bulky, rigid aromatic side chain that can cause structural strain. Glycine is the smallest amino acid and lacks a side chain, so it provides greater flexibility to the protein. This mutation reduces steric hindrance and relieves strain in the protein structure, therefore allowing it to be more adaptable and stable at higher temperatures. By increasing flexibility, the Y127G mutation helps the protein maintain its folded structure under heat stress. | The mutation of tyrosine to glycine at position 127 (Y127G) also increases the protein's thermostability. The mutant melting point is increased to 87.0°C. Tyrosine has a bulky, rigid aromatic side chain that can cause structural strain. Glycine is the smallest amino acid and lacks a side chain, so it provides greater flexibility to the protein. This mutation reduces steric hindrance and relieves strain in the protein structure, therefore allowing it to be more adaptable and stable at higher temperatures. By increasing flexibility, the Y127G mutation helps the protein maintain its folded structure under heat stress. | ||
=== S283 & D238 === | === S283 & D238 === | ||
