title: The role of cep15 in the biosynthesis of chloroeremomycin: reactivation of an ancestral catalytic function.
abstract: The gene clusters of several glycopeptides contain genes that encode COG2120 domain zinc-dependent N-acetylglucosaminyl deacetylases. Recently, a COG2120 protein encoded in the chloroeremomycin gene cluster, Cep15, has been postulated to possess nucleotidyltransferase activity. Here, we demonstrate that Cep15 possesses no catalytic activity and does not have a clear role in chloroeremomycin biosynthesis. This result strongly suggests that cep15 and bal2 are evolutionary artifacts and may be pseudogenes. Comparative sequence analysis with the closely related active Orf2* deacetylase (teicoplanin biosynthesis) reveals an asparagine in place of a metal-binding histidine in the "pseudo-active site" of Cep15. Substitution of this histidine by asparagine in Orf2* abolishes deacetylase activity. Remarkably, the Cep15 N164H mutant is an active deacetylase. To our knowledge, this is the first example of reactivating an ancestral enzymatic role for a bacterial protein by point mutagenesis.
authors.affiliation: University Chemical Laboratory, University of Cambridge, Cambridge, UK.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Truman
authors.forename: Qingzhi
authors.initials: Q
authors.lastname: Fan
authors.forename: Marlene
authors.initials: M
authors.lastname: Röttgen
authors.forename: Evi
authors.initials: E
authors.lastname: Stegmann
authors.forename: Peter F
authors.initials: PF
authors.lastname: Leadlay
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Spencer
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D006655:Histone Deacetylases / Q000737:chemistry / Q000378:metabolism; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D014640:Vancomycin / Q000031:analogs & derivatives* / Q000096:biosynthesis
chemical_list: C112142:chloroeremomycin; D014640:Vancomycin; D006655:Histone Deacetylases