Concept explainers
(a)
To explain: The reason behind the protein cannot remove an alkyl group that attached to guanine.
Concept introduction: O6-alkylguanine-DNA alkyltransferase is an enzyme that is encoded by the MGMT gene in humans. O6-methylguanine is a naturally mutagenic substance. O6-alkylguanine-DNA alkyltransferase coverts these harmful substances back to guanine base and also help to repairing the errors in the replication. A closely resembling protein is produced by yeast and some other organism, but the enzyme lacks a Cys at the active site.
(b)
To determine: The type of repair process to which these proteins most likely to participate.
Concept introduction: O6-alkylguanine-DNA alkyltransferase is an enzyme that is encoded by the MGMT gene in humans. O6-methylguanine is a naturally mutagenic substance. O6-alkylguanine-DNA alkyltransferase coverts these harmful substances back to guanine and also help to repair the errors in the replication. A closely resembling protein is produced by yeast and some other organism, but the enzyme lacks a Cys at the active site.
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FUNDAMENTALS OF BIOCHEMISTRY - LL FD
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