You are undertaking a research project in the lab that studies mutations in proteins of medical importance. You have been assigned to a project on an enzyme called sortase. When incubated with a polypeptide containing the LPXTG motif, it cleaves the peptide bond between the threonine (T) and the glycine (G), as shown in the Figure below.
The Figure also shows that the mechanism of catalysis of this enzyme involves a direct transfer of an electron from the side chain of Cys184 to the peptide substrate, which results in the cleavage of the peptide bond in the substrate. What would be the most likely effect of a missense mutation resulting in a Cys184His substitution on the enzyme's activity?

Question

You are undertaking a research project in the lab that studies mutations in proteins of medical importance. You have been assigned to a project on an enzyme called sortase. When incubated with a polypeptide containing the LPXTG motif, it cleaves the peptide bond between the threonine (T) and the glycine (G), as shown in the Figure below.  
 The Figure also shows that the mechanism of catalysis of this enzyme involves a direct transfer of an electron from the side chain of Cys184 to the peptide substrate, which results in the cleavage of the peptide bond in the substrate.   What would be the most likely effect of a missense mutation resulting in a Cys184His substitution on the enzyme's activity?

Accepted Answer

There will be >1000-fold reduction in activity

Answer

There will be no change in activity

Answer

There will be a minor reduction in activity

Answer

Enzyme’s activity will no longer depend on pH

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You are undertaking a research project in the lab that studies mutations in prot...

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