Bioinformatic Analysis of Topoisomerase IIα Reveals Interdomain Interdependencies and Critical C-Terminal Domain...

Area of Science:

• Biochemistry
• Bioinformatics
• Cancer Biology

Background:

• DNA Topoisomerase IIα (Top2A) is a crucial nuclear enzyme and a validated cancer drug target.
• The intrinsically disordered C-terminal domain (CTD) of Top2A presents a challenge for structural analysis but is a potential site for novel therapeutic interventions.
• Selective inhibition of Top2A is desired to enhance anti-cancer efficacy and minimize off-target side effects.

Purpose of the Study:

• To investigate the sequence-based structure and functional importance of the Top2A C-terminal domain (CTD) using bioinformatic approaches.
• To identify interdependent clusters and conserved regions within Top2A, particularly in the CTD, for potential drug targeting.
• To map functionally significant sites, including low-entropy and phosphorylation sites, within the Top2A CTD.

Main Methods:

• Comparative sequence analysis of Top2A across 105 species.
• Application of bioinformatic tools including PSICalc and Shannon entropy analysis.
• Correlation of identified clusters and low-entropy sites with known mutation data and biochemical activity.

Main Results:

• Identification of large, interdependent clusters spanning multiple domains of Top2A.
• Discovery of CTD-specific clusters, some correlating with altered DNA relaxation activity upon mutation.
• Mapping of low Shannon entropy sites in the CTD, including phosphorylation and charged residues, indicating conserved functional importance.

Conclusions:

• Bioinformatic analysis reveals critical interdependent clusters and conserved sites within the Top2A CTD.
• These identified regions, especially low-entropy and phosphorylation sites, represent promising targets for developing more selective Top2A inhibitors.
• The findings provide a foundation for future experimental validation and the design of novel anti-cancer therapeutics targeting Top2A.