Many archaea encode both histones and Nucleoid-Associated Proteins (NAPs), which we refer to collectively as archaeal DNA Binding Proteins (DBPs). Whether these DBPs jointly work to compact the genome or have distinct functions remains unknown. Here, we have developed the methanogen, Methanosarcina acetivorans, as a platform to study the function of archaeal DBPs in vivo. M. acetivorans encodes one archaeal histone, hmaA, and two copies of the archaea-specific NAP, mc1 (mc1a & mc1b). We found th