Single stranded binding protein: Difference between revisions
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Several specific amino acid residues play essential roles in the binding of ssDNA to SSB. <scene name='56/566528/Phe_60/2'>Phe60</scene> is a key residue involved in binding the ssDNA to the protein, as it has been shown to be the site for cross-linking. Tryptophan and Lysine residues are important in binding as well, as evidenced by modification treatments of lysine and tryptophan residues resulting a complete loss of binding activity for the protein. The two tryptophan residues involved in ssDNA binding are <scene name='56/566528/Trp_40_and_trp_54/1'>Trp40 and Trp54</scene>, which were determined by mutagenesis <ref>PMID:2087220</ref>. | Several specific amino acid residues play essential roles in the binding of ssDNA to SSB. <scene name='56/566528/Phe_60/2'>Phe60</scene> is a key residue involved in binding the ssDNA to the protein, as it has been shown to be the site for cross-linking. Tryptophan and Lysine residues are important in binding as well, as evidenced by modification treatments of lysine and tryptophan residues resulting a complete loss of binding activity for the protein. The two tryptophan residues involved in ssDNA binding are <scene name='56/566528/Trp_40_and_trp_54/1'>Trp40 and Trp54</scene>, which were determined by mutagenesis <ref>PMID:2087220</ref>. | ||
One more key residue in the binding site, <scene name='56/566528/His_55/2'>His55</scene>, was determined by site-specific mutagenesis, as when <scene name='56/566528/His_55/2'>His55</scene> is substituted with Leu it decreases the overall binding affinity for ssDNA. All of these residues are found in a hydrophobic region, which is suitable for nucleotide base interactions. Treatments that modified arginine, cysteine, or tyrosine residues had no effect on binding of SSB to DNA, suggesting that these amino acids are not involved in significant interactions of the protein with the ssDNA. | One more key residue in the binding site, <scene name='56/566528/His_55/2'>His55</scene>, was determined by site-specific mutagenesis, as when <scene name='56/566528/His_55/2'>His55</scene> is substituted with Leu it decreases the overall binding affinity for ssDNA. All of these residues are found in a <scene name='56/566528/Hydrophobic_region/1'>hydrophobic region</scene>, which is suitable for nucleotide base interactions. Treatments that modified arginine, cysteine, or tyrosine residues had no effect on binding of SSB to DNA, suggesting that these amino acids are not involved in significant interactions of the protein with the ssDNA. | ||
====Interactions Between ''E. coli'' SSB and other Proteins==== | ====Interactions Between ''E. coli'' SSB and other Proteins==== | ||