M. Kanemaki et al., MOLECULAR-CLONING OF A RAT 49-KDA TBP-INTERACTING PROTEIN (TIP49) THAT IS HIGHLY HOMOLOGOUS TO THE BACTERIAL RUVB, Biochemical and biophysical research communications, 235(1), 1997, pp. 64-68
TBP as a central component in transcriptional regulation can form comp
lexes with various regulatory factors. Using histidine-tagged TBP for
affinity-purification of TBP-bound proteins, we isolated a 49-kD prote
in termed TBP-interacting protein 49 (TIP49) from rat liver nuclear ex
tracts, We cloned the entire cDNA of TIP49 encoding a novel polypeptid
e of 456 amino acids, and thereafter established an FM3A cell line tha
t constitutively expressed an epitope-tagged TBP. Immunoprecipitation
analysis of the cell extracts indicated that TIP49 and TBP were presen
t in an identical complex. Interestingly, the amino acid sequence of T
IP49 exhibited high similarity to those sequences of the RuvB bacteria
l recombination factors which direct branch migration of the Holliday
junction and contain the Walker A and B motifs responsible for ATP bin
ding and ATP hydrolysis. These findings suggest that TIP49 is a putati
ve ATP-dependent DNA helicase. (C) 1997 Academic Press.