Isolation and characterization of cDNAs encoding transcription factor IIB from Arabidopsis and soybean

Abstract

Clones containing the complete coding regions for transcription factor IIB (TFIIB) were isolated from cDNA libraries of Arabidopsis and soybean. The predicted protein sequences for TFIIB from these two species are highly homologous and contain the same structural motifs and organization as seen in other eukaryotes and Archaebacteria. Southern and Northern blots and primer extension for Arabidopsis TFIIB indicate a low copy number gene encodes a transcript of 1400 nt with a leader of 180 nt. Phylogeny analysis places the plant proteins into one group nearly equidistant from metazoans, fungi, and Archaebacteria.