3CLC:
reference: Structural analysis of the genetic switch that regulates the expression of restriction-modification genes., McGeehan JE, Streeter SD, Thresh SJ, Ball N, Ravelli RB, Kneale GG, Nucleic Acids Res. 2008 Aug;36(14):4778-87. Epub 2008 Jul 21. PMID: 18644840

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