Sandbox/Judy Voet/PFK: Difference between revisions
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What happens to the central polypeptide helical segment (residues 149-164) in the R to T transition? What does this do to the relative positions of the negatively charged Glu 161 and the positively charged Arg 162? Click on "F6P site". What influence would the presence of the carboxylate group of Glu 161 have on the phosphate group of F6P were it to bind in the active site? Does this explain, at least in part, why T state PFK has low affinity for F6P? Go to View 2. Closeup, for a closeup of the F6P-sidechain interactions. Center the molecules by choosing "pickcenter" from the "tools" menu and clicking on athe atom you'd like to be in the center. Slide the "zoom" slider to enlarge the view. | What happens to the central polypeptide helical segment (residues 149-164) in the R to T transition? What does this do to the relative positions of the negatively charged Glu 161 and the positively charged Arg 162? Click on "F6P site". What influence would the presence of the carboxylate group of Glu 161 have on the phosphate group of F6P were it to bind in the active site? Does this explain, at least in part, why T state PFK has low affinity for F6P? Go to View 2. Closeup, for a closeup of the F6P-sidechain interactions. Center the molecules by choosing "pickcenter" from the "tools" menu and clicking on athe atom you'd like to be in the center. Slide the "zoom" slider to enlarge the view. | ||
==Site-Directed Mutagenesis== | ==Site-Directed Mutagenesis== | ||
Three mutant PFKs have been made, R162A, E161A and R162A/E161A <ref>PMID:10759544</ref>. The R162A mutation caused a 30-fold decrease in F6P binding. Surprisingly, the E161A mutation had little effect on the ability of PEP to inhibit F6P binding. A more complicated analysis of the allosteric effects of PFK have therefore been proposed. | Three mutant PFKs have been made, R162A, E161A and R162A/E161A <ref>PMID:10759544</ref>. The R162A mutation caused a 30-fold decrease in F6P binding. Surprisingly, the E161A mutation had little effect on the ability of PEP to inhibit F6P binding. A more complicated analysis of the allosteric effects of PFK have therefore been proposed.<ref>PMID: 14717614</ref> | ||
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==References== | ==References== | ||
<references/> | <references/> | ||