5A1Q:
reference: STAC-A New Domain Associated with Transmembrane Solute Transport and Two-Component Signal Transduction Systems., Korycinski M, Albrecht R, Ursinus A, Hartmann MD, Coles M, Martin J, Dunin-Horkawicz S, Lupas AN, J Mol Biol. 2015 Oct 9;427(20):3327-39. doi: 10.1016/j.jmb.2015.08.017. Epub 2015, Aug 28. PMID: 26321252

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