The phosphoCTD-interacting domain of Topoisomerase I.
The N-terminal domain (NTD) of Drosophila melanogaster (Dm) Topoisomerase I has been shown to bind to RNA polymerase II, but the domain of RNAPII with which it interacts is not known. Using bacterially-expressed fusion proteins carrying all or half of the NTDs of Dm and human (Homo sapiens, Hs) Topo I, we demonstrate that the N-terminal half of each NTD binds directly to the hyperphosphorylated C-terminal repeat domain (phosphoCTD) of the largest RNAPII subunit, Rpb1. Thus, the amino terminal segment of metazoan Topo I (1-157 for Dm and 1-114 for Hs) contains a novel phosphoCTD-interacting domain that we designate the Topo I-Rpb1 interacting (TRI) domain. The long-known in vivo association of Topo I with active genes presumably can be attributed, wholly or in part, to the TRI domain-mediated binding of Topo I to the phosphoCTD of transcribing RNAPII.
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Related Subject Headings
- Sequence Alignment
- Recombinant Fusion Proteins
- Protein Structure, Tertiary
- Phosphorylation
- Molecular Sequence Data
- Humans
- Drosophila melanogaster
- DNA Topoisomerases, Type I
- Chickens
- Cattle
Citation
Published In
DOI
EISSN
Publication Date
Volume
Issue
Start / End Page
Location
Related Subject Headings
- Sequence Alignment
- Recombinant Fusion Proteins
- Protein Structure, Tertiary
- Phosphorylation
- Molecular Sequence Data
- Humans
- Drosophila melanogaster
- DNA Topoisomerases, Type I
- Chickens
- Cattle