4RUL

Crystal structure of full-length E.Coli topoisomerase I in complex with ssDNA

Summary for 4RUL

• Entry DOI: 10.2210/pdb4rul/pdb
• Related: 3PWT 3PX7
• Descriptor: DNA topoisomerase 1, single strand DNA, ZINC ION, ... (6 entities in total)
• Functional Keywords: topoisomerase 1a, isomerase-dna complex, isomerase/dna
• Biological source: Escherichia coli DH1; More
• Total number of polymer chains: 2
• Total formula weight: 107370.85

Authors

Tan, K.,Chen, B.,Tse-Dinh, Y.C. (deposition date: 2014-11-20, release date: 2015-11-04, Last modification date: 2023-09-20)

Primary citation

Tan, K.,Zhou, Q.,Cheng, B.,Zhang, Z.,Joachimiak, A.,Tse-Dinh, Y.C.
Structural basis for suppression of hypernegative DNA supercoiling by E. coli topoisomerase I.
Nucleic Acids Res., 43:11031-11046, 2015

PubMed Abstract: Escherichia coli topoisomerase I has an essential function in preventing hypernegative supercoiling of DNA. A full length structure of E. coli topoisomerase I reported here shows how the C-terminal domains bind single-stranded DNA (ssDNA) to recognize the accumulation of negative supercoils in duplex DNA. These C-terminal domains of E. coli topoisomerase I are known to interact with RNA polymerase, and two flexible linkers within the C-terminal domains may assist in the movement of the ssDNA for the rapid removal of transcription driven negative supercoils. The structure has also unveiled for the first time how the 4-Cys zinc ribbon domain and zinc ribbon-like domain bind ssDNA with primarily π-stacking interactions. This novel structure, in combination with new biochemical data, provides important insights into the mechanism of genome regulation by type IA topoisomerases that is essential for life, as well as the structures of homologous type IA TOP3α and TOP3β from higher eukaryotes that also have multiple 4-Cys zinc ribbon domains required for their physiological functions.

PubMed: 26490962
DOI: 10.1093/nar/gkv1073

Experimental method

X-RAY DIFFRACTION (2.9 Å)