Identification of a Putative BRF Homologue in the Genome of Caenorhabditis elegans

Abstract

We have identified a putative gene within the Caenorhabditis elegans genome which has the potential to encode a protein homologous to BRF, an RNA polymerase IH general transcription factor. The predicted protein shares very similar overall structure with human and yeast BRF. In particular, its N-terminal half comprises a zinc-ribbon motif and a TR domain which is also present in the cyclin box. The C. elegans protein is more similar to human BRF than to the yeast BRF proteins, as would be expected from an evolutionary standpoint. Alignment of the C. elegans protein with the four known BRF proteins reveals two blocks conserved between all five sequences within the diverged C-terminal region. Profile searches using these regions suggest that they may contain evolu-tionarily conserved motifs. These comparisons provide insight into the structure and function of an important transcription factor.

Key Words:

• BRF
• Caenorhabditis elegans
• RNA polymerase IIIB
• TFIIB-related factor
• TFIIIB
• cyclin box