title: Biochemical and structural studies of conserved Maf proteins revealed nucleotide pyrophosphatases with a preference for modified nucleotides.
abstract: Maf (for multicopy associated filamentation) proteins represent a large family of conserved proteins implicated in cell division arrest but whose biochemical activity remains unknown. Here, we show that the prokaryotic and eukaryotic Maf proteins exhibit nucleotide pyrophosphatase activity against 5-methyl-UTP, pseudo-UTP, 5-methyl-CTP, and 7-methyl-GTP, which represent the most abundant modified bases in all organisms, as well as against canonical nucleotides dTTP, UTP, and CTP. Overexpression of the Maf protein YhdE in E. coli cells increased intracellular levels of dTMP and UMP, confirming that dTTP and UTP are the in vivo substrates of this protein. Crystal structures and site-directed mutagenesis of Maf proteins revealed the determinants of their activity and substrate specificity. Thus, pyrophosphatase activity of Maf proteins toward canonical and modified nucleotides might provide the molecular mechanism for a dual role of these proteins in cell division arrest and house cleaning.
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada.
authors.forename: Anatoli
authors.initials: A
authors.lastname: Tchigvintsev
authors.forename: Dmitri
authors.initials: D
authors.lastname: Tchigvintsev
authors.forename: Robert
authors.initials: R
authors.lastname: Flick
authors.forename: Ana
authors.initials: A
authors.lastname: Popovic
authors.forename: Aiping
authors.initials: A
authors.lastname: Dong
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Xu
authors.forename: Greg
authors.initials: G
authors.lastname: Brown
authors.forename: Wenyun
authors.initials: W
authors.lastname: Lu
authors.forename: Hong
authors.initials: H
authors.lastname: Wu
authors.forename: Hong
authors.initials: H
authors.lastname: Cui
authors.forename: Ludmila
authors.initials: L
authors.lastname: Dombrowski
authors.forename: Jeong Chan
authors.initials: JC
authors.lastname: Joo
authors.forename: Natalia
authors.initials: N
authors.lastname: Beloglazova
authors.forename: Jinrong
authors.initials: J
authors.lastname: Min
authors.forename: Alexei
authors.initials: A
authors.lastname: Savchenko
authors.forename: Amy A
authors.initials: AA
authors.lastname: Caudy
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Rabinowitz
authors.forename: Alexey G
authors.initials: AG
authors.lastname: Murzin
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Yakunin
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology; D029968:Escherichia coli Proteins / Q000378:metabolism*; D006801:Humans; D050977:Maf Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009711:Nucleotides / Q000737:chemistry* / Q000378:metabolism*; D011755:Pyrophosphatases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D012486:Salmonella typhimurium / Q000201:enzymology / Q000235:genetics; D013379:Substrate Specificity
chemical_list: D029968:Escherichia coli Proteins; D050977:Maf Transcription Factors; D009711:Nucleotides; D011755:Pyrophosphatases; C000607522:YhdE protein, E coli; C021899:nucleotide pyrophosphatase