Isolation and characterization of a cDNA encoding a human TFIID subunit containing a variety of putative structural...

A cDNA encoding human TFIID subunit p30 beta (hp30 beta) was isolated and sequenced. Comparison of the deduced 211 amino acid (aa) sequence with that of Drosophila melanogaster p30 beta (dp30 beta) showed 45% identity in overall length, and subunits with highly conserved C-terminal (81% identity) and less conserved N-terminal (21% identity) regions. Three acidic and basic regions were alternately placed. Potent target sites for protein kinases and a putative nuclear localization signal (NLS) were located in the N-terminal region. Interestingly, analysis of the aa sequence of p30 beta led us to find several interesting structural motifs/regions including 1) direct repeats, 2) a region similar to histone H4 between the two direct repeats and 3) acidic and hydrophobic aa surfaces in the potent helical region. Northern blot analysis showed ubiquitous expression of mRNA corresponding to hp 30 beta.