Dihydrodipicolinate synthase: Difference between revisions
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<StructureSection load='3pue' size='350' side='right' caption='Structure of dihydrodipicolinate synthase complex with lysine, glycerol and sulfate (PDB entry [[3pue]])' scene=''> | |||
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Members of the NAL protein subfamily have very similar active sites and a single amino acid substitution can significantly change their function. For example, NAL ([[1nal]]) gets DHDPS activity by substitution of a <scene name='2v9d/Leucine142/2'>leucine</scene> <font color='orange'><b>(orange)</b></font> to <scene name='2v9d/Arginine142/2'>arginine</scene> <font color='blue'><b>(blue)</b></font> at position 142. The possible active site region of <font color='cyan'><b>YagE</b></font> demonstrates closest sequence similarity to the active site of <font color='magenta'><b>KDG aldolase of SsKDGA</b></font> ([[1w3i]]) and <font color='black'><b>NAL of EcNAL</b></font> ([[1nal]]) (yellow), suggesting that this protein can perform either of these functions. Although the active site of EcDHDPS ([[1xky]]) and BaDHDPS ([[2ats]]) shows similarities, the important residue that differentiates between NAL and DHDPS, namely Leu142 (in [[1nal]]), is also present in YagE <scene name='2v9d/Leucine150/2'>(Leu150)</scene> <font color='cyan'><b>(labeled cyan)</b></font> at that particular position suggesting that YagE performs a NAL-related function rather than DHDPS-related one. In conclusion, the high-resolution X-ray structure of YagE provides a clue that it probably belongs to the NAL subfamily of proteins. Although the exact molecular function of YagE is still unknown, its structure provides a handle for understanding its molecular function based on knowledge about conserved residues of the putative active site. | Members of the NAL protein subfamily have very similar active sites and a single amino acid substitution can significantly change their function. For example, NAL ([[1nal]]) gets DHDPS activity by substitution of a <scene name='2v9d/Leucine142/2'>leucine</scene> <font color='orange'><b>(orange)</b></font> to <scene name='2v9d/Arginine142/2'>arginine</scene> <font color='blue'><b>(blue)</b></font> at position 142. The possible active site region of <font color='cyan'><b>YagE</b></font> demonstrates closest sequence similarity to the active site of <font color='magenta'><b>KDG aldolase of SsKDGA</b></font> ([[1w3i]]) and <font color='black'><b>NAL of EcNAL</b></font> ([[1nal]]) (yellow), suggesting that this protein can perform either of these functions. Although the active site of EcDHDPS ([[1xky]]) and BaDHDPS ([[2ats]]) shows similarities, the important residue that differentiates between NAL and DHDPS, namely Leu142 (in [[1nal]]), is also present in YagE <scene name='2v9d/Leucine150/2'>(Leu150)</scene> <font color='cyan'><b>(labeled cyan)</b></font> at that particular position suggesting that YagE performs a NAL-related function rather than DHDPS-related one. In conclusion, the high-resolution X-ray structure of YagE provides a clue that it probably belongs to the NAL subfamily of proteins. Although the exact molecular function of YagE is still unknown, its structure provides a handle for understanding its molecular function based on knowledge about conserved residues of the putative active site. | ||
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==3D structures of dihydrodipicolinate synthase== | ==3D structures of dihydrodipicolinate synthase== | ||