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Publication Abstract from PubMed

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 CI58 investigated here, is necessary for high-affinity binding to DNA. The crystal structure of the dimerization region (CTD1 ) 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 CI58 in complex with a palindromic operator site, showing that the two NTDs bind on opposing sides of the DNA helix.

Structural basis of the bacteriophage TP901-1 CI repressor dimerization and interaction with DNA.,Rasmussen KK, Varming AK, Schmidt SN, Frandsen KEH, Thulstrup PW, Jensen MR, Lo Leggio L FEBS Lett. 2018 Apr 23. doi: 10.1002/1873-3468.13060. PMID:29683476^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.