NS5B: Difference between revisions
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The template strand is seen entering through a gap in the fingers domain. An incoming dTTP that would extend the primer strand lines up with the NS5B active site and duplex DNA exits the enzyme through the large central hole in the closed active site formed by the unusual contacts between the fingers and thumb domains. | The template strand is seen entering through a gap in the fingers domain. An incoming dTTP that would extend the primer strand lines up with the NS5B active site and duplex DNA exits the enzyme through the large central hole in the closed active site formed by the unusual contacts between the fingers and thumb domains. | ||
<applet load='2HAI_catalytic3.pdb' size='400' frame='true' align='right' caption='Figure 3.' /> | <applet load='2HAI_catalytic3.pdb' size='400' frame='true' align='right' caption='Figure 3.' /> | ||
'''Figure 3''' explores empirically determined sites of protein-ssRNA interactions. The highlighted <scene name='NS5B/Ns5b_rna_interactions/1'>peptide segments</scene> were each identified without x-ray crystallography or NMR. These RNA binding peptides were identified by cross linking single stranded RNA to NS5B followed by a tryptic digest of the protein, then purification of the RNA bound peptide segments by affinity (for the RNA) chromatography. The segments of peptide that stuck to the column meaning they had been cross linked to RNA were then analyzed with MALDI mass spectrometry. It is interesting that all of the contacts were in the <scene name='NS5B/Native_ns5b/3'>fingers domain.</scene> This could be in part due to the fact that single stranded RNA was cross linked to the enzyme, the fingers domain is thought to bind templating ssRNA. | '''Figure 3''' explores empirically determined sites of protein-ssRNA interactions. The highlighted <scene name='NS5B/Ns5b_rna_interactions/1'>peptide segments</scene> were each identified without x-ray crystallography or NMR. These RNA binding peptides were identified by cross linking single stranded RNA to NS5B followed by a tryptic digest of the protein, then purification of the RNA bound peptide segments by affinity (for the RNA) chromatography. The segments of peptide that stuck to the column meaning they had been cross linked to RNA were then analyzed with MALDI mass spectrometry. It is interesting that all of the contacts were in the <scene name='NS5B/Native_ns5b/3'>fingers domain.</scene> This could be in part due to the fact that single stranded RNA was cross linked to the enzyme, the fingers domain is thought to bind templating ssRNA while other regions of the polymerase would bind duplex RNA. | ||