6IVS:
reference: Alternative sigmaI/anti-sigmaI factors represent a unique form of bacterial sigma/anti-sigma complex., Wei Z, Chen C, Liu YJ, Dong S, Li J, Qi K, Liu S, Ding X, Ortiz de Ora L, Munoz-Gutierrez I, Li Y, Yao H, Lamed R, Bayer EA, Cui Q, Feng Y, Nucleic Acids Res. 2019 May 20. pii: 5490815. doi: 10.1093/nar/gkz355. PMID: 31106374

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