3LPE:
reference: Spt4/5 stimulates transcription elongation through the RNA polymerase clamp coiled-coil motif., Hirtreiter A, Damsma GE, Cheung AC, Klose D, Grohmann D, Vojnic E, Martin AC, Cramer P, Werner F, Nucleic Acids Res. 2010 Jul 1;38(12):4040-51. Epub 2010 Mar 2. PMID: 20197319

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