The small nuclear RNA-activating protein 190 Myb DNA binding domain stimulates TATA box-binding protein-TATA box recognition.
Human U6 small nuclear RNA (snRNA) gene transcription by RNA polymerase III requires cooperative promoter binding involving the snRNA-activating protein complex (SNAP(c)) and the TATA-box binding protein (TBP). To investigate the role of SNAP(c) for TBP function at U6 promoters, TBP recruitment assays were performed using full-length TBP and a mini-SNAP(c) containing SNAP43, SNAP50, and a truncated SNAP190. Mini-SNAP(c) efficiently recruits TBP to the U6 TATA box, and two SNAP(c) subunits, SNAP43 and SNAP190, directly interact with the TBP DNA binding domain. Truncated SNAP190 containing only the Myb DNA binding domain is sufficient for TBP recruitment to the TATA box. Therefore, the SNAP190 Myb domain functions both to specifically recognize the proximal sequence element present in the core promoters of human snRNA genes and to stimulate TBP recognition of the neighboring TATA box present in human U6 snRNA promoters. The SNAP190 Myb domain also stimulates complex assembly with TBP and Brf2, a subunit of a snRNA-specific TFIIIB complex. Thus, interactions between the DNA binding domains of SNAP190 and TBP at juxtaposed promoter elements define the assembly of a RNA polymerase III-specific preinitiation complex.
Hinkley
Craig S
CS
Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA.
Hirsch
Heather A
HA
Gu
Liping
L
LaMere
Brandon
B
Henry
R William
RW
D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008954:Models, Biological; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012342:RNA, Small Nuclear / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D035181:TATA-Box Binding Protein / Q000737:chemistry*; D035361:Transcription Factor TFIIIB / Q000737:chemistry / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism
D004268:DNA-Binding Proteins; D012342:RNA, Small Nuclear; D011993:Recombinant Fusion Proteins; C093069:SNAPC1 protein, human; C116351:SNAPC4 protein, human; D035181:TATA-Box Binding Protein; D035361:Transcription Factor TFIIIB; D014157:Transcription Factors; C405486:U6 small nuclear RNA; C091750:ZFP36L2 protein, human; D005982:Glutathione Transferase; D005978:Glutathione