creators_name: Kaur, Gurmeet
creators_name: Iyer, Lakshminarayan M
creators_name: Subramanian, Srikrishna
creators_name: Aravind, L
type: article
datestamp: 2018-08-09 06:17:23
lastmod: 2018-08-09 06:17:23
metadata_visibility: show
title: Evolutionary convergence and divergence in archaeal chromosomal proteins and Chromo-like domains from bacteria and eukaryotes.
ispublished: pub
subjects: QR
note: Open Access article
abstract: SH3-fold-β-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.
date: 2018-04-18
date_type: published
publication: Scientific reports
volume: 8
number: 1
publisher: Nature Publishing Group.
pagerange: 6196
refereed: TRUE
issn: 2045-2322
official_url: https://www.nature.com/articles/s41598-018-24467-z
citation:   Kaur, Gurmeet and Iyer, Lakshminarayan M and Subramanian, Srikrishna and Aravind, L  (2018) Evolutionary convergence and divergence in archaeal chromosomal proteins and Chromo-like domains from bacteria and eukaryotes.  Scientific reports, 8 (1).  p. 6196.  ISSN 2045-2322