title: Implications for the evolution of eukaryotic amino-terminal acetyltransferase (NAT) enzymes from the structure of an archaeal ortholog.
abstract: Amino-terminal acetylation is a ubiquitous modification in eukaryotes that is involved in a growing number of biological processes. There are six known eukaryotic amino-terminal acetyltransferases (NATs), which are differentiated from one another on the basis of substrate specificity. To date, two eukaryotic NATs, NatA and NatE, have been structurally characterized, of which NatA will acetylate the α-amino group of a number of nonmethionine amino-terminal residue substrates such as serine; NatE requires a substrate amino-terminal methionine residue for activity. Interestingly, these two NATs use different catalytic strategies to accomplish substrate-specific acetylation. In archaea, where this modification is less prevalent, only one NAT enzyme has been identified. Surprisingly, this enzyme is able to acetylate NatA and NatE substrates and is believed to represent an ancestral NAT variant from which the eukaryotic NAT machinery evolved. To gain insight into the evolution of NAT enzymes, we determined the X-ray crystal structure of an archaeal NAT from Sulfolobus solfataricus (ssNAT). Through the use of mutagenesis and kinetic analysis, we show that the active site of ssNAT represents a hybrid of the NatA and NatE active sites, and we highlight features of this protein that allow it to facilitate catalysis of distinct substrates through different catalytic strategies, which is a unique characteristic of this enzyme. Taken together, the structural and biochemical data presented here have implications for the evolution of eukaryotic NAT enzymes and the substrate specificities therein.
authors: Program in Gene Expression and Regulation, The Wistar Institute, Philadelphia, PA 19104, USA.
authors: Glen
authors: G
authors: Liszczak
authors: Ronen
authors: R
authors: Marmorstein
mesh_terms: D000105:Acetyl Coenzyme A / Q000737:chemistry / Q000378:metabolism; D000107:Acetylation; D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020134:Catalytic Domain / Q000235:genetics; D018360:Crystallography, X-Ray; D005057:Eukaryotic Cells / Q000201:enzymology; D019143:Evolution, Molecular; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D063209:N-Terminal Acetyltransferase A / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D063213:N-Terminal Acetyltransferase E / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D063206:N-Terminal Acetyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D048229:Sulfolobus solfataricus / Q000201:enzymology*
chemical_list: D019843:Archaeal Proteins; D000105:Acetyl Coenzyme A; D063209:N-Terminal Acetyltransferase A; D063213:N-Terminal Acetyltransferase E; D063206:N-Terminal Acetyltransferases
keywords: X-ray crystallography; enzymology; evolutionary biology; structural biology
references: EMBO J. 1992 Jun;11(6):2087-93
references: 1600941
references: Cell. 1999 Apr 30;97(3):361-9
references: 10319816
references: Science. 2011 Nov 4;334(6056):674-8
references: 21940857
references: J Biol Chem. 2001 Jun 8;276(23):20154-9
references: 11274203
references: J Biol Chem. 2001 May 11;276(19):16328-34
references: 11278591
references: Mol Microbiol. 2007 Jun;64(6):1540-8
references: 17511810
references: Archaea. 2010 Sep 16;2010:
references: 20885971
references: J Cell Biochem. 2008 Feb 1;103(2):492-508
references: 17541948
references: J Mol Biol. 2006 Oct 6;362(5):915-24
references: 16950390
references: Cell. 2011 Aug 19;146(4):607-20
references: 21854985
references: Biochem Biophys Res Commun. 2003 Aug 15;308(1):1-11
references: 12890471
references: PLoS Biol. 2011 May;9(5):e1001073
references: 21655302
references: Cell Mol Life Sci. 2001 May;58(5-6):693-703
references: 11437231
references: Nat Struct Mol Biol. 2013 Sep;20(9):1098-105
references: 23912279
references: Science. 2010 Feb 19;327(5968):973-7
references: 20110468
references: J Biol Chem. 2003 Aug 15;278(33):30686-97
references: 12783868
references: PLoS Genet. 2011 Jul;7(7):e1002169
references: 21750686
references: Proc Natl Acad Sci U S A. 2009 May 19;106(20):8157-62
references: 19420222
references: J Mol Biol. 1999 Dec 17;294(5):1311-25
references: 10600387
references: J Proteome Res. 2008 Nov;7(11):5033-9
references: 18816081
references: J Biol Chem. 2009 Nov 6;284(45):31122-9
references: 19744929
references: J Biol Chem. 2011 Oct 21;286(42):37002-10
references: 21900231
references: J Proteome Res. 2007 Jun;6(6):2195-204
references: 17444671
references: Mol Cell Biol. 2003 Oct;23(20):7403-14
references: 14517307
references: J Biol Chem. 2003 Oct 3;278(40):38109-12
references: 12915400