Discovery and substrate specificity engineering of nucleotide halogenases.

Area of Science:

• Biochemistry
• Enzymology
• Medicinal Chemistry

Background:

• C2'-halogenation is crucial for improving drug-like properties of nucleotide analogs.
• The nucleotide halogenase AdaV can halogenate 2'-deoxyadenosine-5'-monophosphate (dAMP), but its substrate scope is limited.
• Expanding the range of nucleotide analogs amenable to halogenation is essential for drug discovery.

Purpose of the Study:

• To identify and characterize novel halogenases capable of modifying 2'-deoxyguanosine monophosphate (dGMP).
• To investigate the structural determinants of nucleotide specificity in halogenases.
• To engineer halogenase specificity for broader substrate applicability.

Main Methods:

• Enzyme screening and characterization.
• Site-directed mutagenesis.
• Computational modeling of enzyme-substrate interactions.
• Biochemical assays to assess halogenation activity.

Main Results:

• Two novel halogenases capable of dGMP halogenation were identified, expanding the known family of nucleotide halogenases.
• Computational studies indicated that the phosphate-binding pose dictates enzyme specificity.
• Engineering efforts successfully altered the substrate specificity of the identified halogenases by mutating second-sphere residues.

Conclusions:

• This study introduces new tools for nucleotide analog modification, specifically for dGMP.
• The findings provide critical insights into the mechanism of halogenase substrate specificity.
• Engineered halogenases offer expanded applications in medicinal chemistry and drug development.