C2H2 proteins: Evolutionary aspects of domain architecture and diversification

Area of Science:

• Molecular Biology
• Genomics
• Evolutionary Biology

Background:

• C2H2 proteins represent the largest class of transcription factors in higher eukaryotes.
• These proteins utilize C2H2-type zinc finger domains for specific DNA binding.
• Their critical roles in gene expression and chromosome architecture are well-established.

Purpose of the Study:

• To review the domain architecture of C2H2 proteins.
• To investigate the evolutionary origins of C2H2 zinc fingers.
• To compare the organization of C2H2 domains across different organisms.

Main Methods:

• Proteome-wide investigation of protein domain clustering.
• Comparative analysis of transcription factor domain architecture.

Main Results:

• A significant difference in C2H2 domain organization was observed between plants and metazoans.
• Metazoan transcription factors characteristically possess clustered C2H2 domains, often linked by a TGEKP consensus sequence.
• The size of these C2H2 clusters varies, increasing with SCAN and KRAB domains in higher metazoans.

Conclusions:

• The clustered arrangement of C2H2 domains in metazoans suggests a distinct evolutionary path for gene regulation.
• Increasing complexity in gene regulatory networks correlates with larger C2H2 clusters and associated domains.
• This domain organization highlights the intricate mechanisms governing gene expression in multicellular organisms.