@article{open2100,
          volume = {8},
          number = {1},
           month = {April},
          author = {Gurmeet Kaur and Lakshminarayan M Iyer and Srikrishna Subramanian and L Aravind},
            note = {Open Access article},
           title = {Evolutionary convergence and divergence in archaeal chromosomal proteins and Chromo-like domains from bacteria and eukaryotes.},
       publisher = {Nature Publishing Group.},
            year = {2018},
         journal = {Scientific reports},
           pages = {6196},
             url = {http://crdd.osdd.net/open/2100/},
        abstract = {SH3-fold-{\ensuremath{\beta}}-barrel domains of the chromo-like superfamily recognize epigenetic marks in eukaryotic proteins. Their provenance has been placed either in archaea, based on apparent structural similarity to chromatin-compacting Sul7d and Cren7 proteins, or in bacteria based on the presence of sequence homologs. Using sequence and structural evidence we establish that the archaeal Cren7/Sul7 proteins emerged from a zinc ribbon (ZnR) ancestor. Further, we show that the ancestral eukaryotic chromo-like domains evolved from bacterial versions, likely acquired from early endosymbioses, which already possessed an aromatic cage for recognition of modified amino-groups. These bacterial versions are part of a radiation of secreted SH3-fold domains, which spawned both chromo-like domains and classical SH3 domains in the context of peptide-recognition in the peptidoglycan or the extracellular matrix. This establishes that Cren7/Sul7 converged to a "SH3"-like state from a ZnR precursor via the loss of metal-chelation and acquisition of stronger hydrophobic interactions; it is unlikely to have participated in the evolution of the chromo-like domains. We show that archaea possess several Cren7/Sul7-related proteins with intact Zn-chelating ligands, which we predict to play previously unstudied roles in chromosome segregation during cell-division comparable to the PRC barrel and CdvA domain proteins.}
}