5FGM:
reference: In Streptomyces coelicolor SigR, methionine at the -35 element interacting region 4 confers the -31'-adenine base selectivity., Kim KY, Park JK, Park S, Biochem Biophys Res Commun. 2016 Feb 5;470(2):257-62. doi:, 10.1016/j.bbrc.2016.01.075. Epub 2016 Jan 14. PMID: 26775842

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