6FXA

Dimerization domain of TP901-1 CI repressor

Summary for 6FXA

• Entry DOI: 10.2210/pdb6fxa/pdb
• Related: 3ZHI 5A7L
• Descriptor: CI, SULFATE ION (3 entities in total)
• Functional Keywords: ci repressor, dimerization domain, helical hook, transcription, viral protein
• Biological source: Lactococcus phage TP901-1
• Total number of polymer chains: 6
• Total formula weight: 25252.62

Authors

Varming, A.K.,Rasmussen, K.K.,Lo Leggio, L. (deposition date: 2018-03-08, release date: 2018-05-30, Last modification date: 2024-05-08)

Primary citation

Rasmussen, K.K.,Varming, A.K.,Schmidt, S.N.,Frandsen, K.E.H.,Thulstrup, P.W.,Jensen, M.R.,Lo Leggio, L.
Structural basis of the bacteriophage TP901-1 CI repressor dimerization and interaction with DNA.
FEBS Lett., 592:1738-1750, 2018

PubMed Abstract: Temperate bacteriophages are known for their bistability, which in TP901-1 is controlled by two proteins, CI and MOR. Clear 1 repressor (CI) is hexameric and binds three palindromic operator sites via an N-terminal helix-turn-helix domain (NTD). A dimeric form, such as the truncated CI∆58 investigated here, is necessary for high-affinity binding to DNA. The crystal structure of the dimerization region (CTD ) is determined here, showing that it forms a pair of helical hooks. This newly determined structure is used together with the known crystal structure of the CI-NTD and small angle X-ray scattering data, to determine the solution structure of CI∆58 in complex with a palindromic operator site, showing that the two NTDs bind on opposing sides of the DNA helix.

PubMed: 29683476
DOI: 10.1002/1873-3468.13060

Experimental method

X-RAY DIFFRACTION (1.5 Å)