title: 3-to-1: unraveling structural transitions in ureases.
abstract: Ureases are nickel-dependent enzymes which catalyze the hydrolysis of urea to ammonia and carbamate. Despite the apparent wealth of data on ureases, many crucial aspects regarding these enzymes are still unknown, or constitute matter for ongoing debates. One of these is most certainly their structural organization: ureases from plants and fungi have a single unit, while bacterial and archaean ones have three-chained structures. However, the primitive state of these proteins--single- or three-chained--is yet unknown, despite many efforts in the field. Through phylogenetic inference using three different datasets and two different algorithms, we were able to observe chain number transitions displayed in a 3-to-1 fashion. Our results imply that the ancestral state for ureases is the three-chained organization, with single-chained ureases deriving from them. The two-chained variants are not evolutionary intermediates. A fusion process, different from those already studied, may explain this structural transition.
authors.affiliation: Graduate Program in Cellular and Molecular Biology, Center of Biotechnology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil. rodrigobraun@cbiot.ufrgs.br
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Ligabue-Braun
authors.forename: Fábio Carrer
authors.initials: FC
authors.lastname: Andreis
authors.forename: Hugo
authors.initials: H
authors.lastname: Verli
authors.forename: Célia Regina
authors.initials: CR
authors.lastname: Carlini
mesh_terms: D001105:Archaea / Q000145:classification / Q000201:enzymology; D001419:Bacteria / Q000145:classification / Q000201:enzymology; D005658:Fungi / Q000145:classification / Q000201:enzymology; D008958:Models, Molecular; D010802:Phylogeny; D010944:Plants / Q000145:classification / Q000201:enzymology; D017434:Protein Structure, Tertiary; D014510:Urease / Q000737:chemistry* / Q000235:genetics
chemical_list: D014510:Urease