title: Plant phenylacetaldehyde synthase is a bifunctional homotetrameric enzyme that catalyzes phenylalanine decarboxylation and oxidation.
abstract: We have isolated and characterized Petunia hybrida cv. Mitchell phenylacetaldehyde synthase (PAAS), which catalyzes the formation of phenylacetaldehyde, a constituent of floral scent. PAAS is a cytosolic homotetrameric enzyme that belongs to group II pyridoxal 5'-phosphate-dependent amino-acid decarboxylases and shares extensive amino acid identity (approximately 65%) with plant L-tyrosine/3,4-dihydroxy-L-phenylalanine and L-tryptophan decarboxylases. It displays a strict specificity for phenylalanine with an apparent Km of 1.2 mM. PAAS is a bifunctional enzyme that catalyzes the unprecedented efficient coupling of phenylalanine decarboxylation to oxidation, generating phenylacetaldehyde, CO2, ammonia, and hydrogen peroxide in stoichiometric amounts.
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907-2010, USA.
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Kaminaga
authors.forename: Jennifer
authors.initials: J
authors.lastname: Schnepp
authors.forename: Greg
authors.initials: G
authors.lastname: Peel
authors.forename: Christine M
authors.initials: CM
authors.lastname: Kish
authors.forename: Gili
authors.initials: G
authors.lastname: Ben-Nissan
authors.forename: David
authors.initials: D
authors.lastname: Weiss
authors.forename: Irina
authors.initials: I
authors.lastname: Orlova
authors.forename: Orly
authors.initials: O
authors.lastname: Lavie
authors.forename: David
authors.initials: D
authors.lastname: Rhodes
authors.forename: Karl
authors.initials: K
authors.lastname: Wood
authors.forename: D Marshall
authors.initials: DM
authors.lastname: Porterfield
authors.forename: Arthur J L
authors.initials: AJ
authors.lastname: Cooper
authors.forename: John V
authors.initials: JV
authors.lastname: Schloss
authors.forename: Eran
authors.initials: E
authors.lastname: Pichersky
authors.forename: Alexander
authors.initials: A
authors.lastname: Vainstein
authors.forename: Natalia
authors.initials: N
authors.lastname: Dudareva
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D002384:Catalysis; D003653:Decarboxylation; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D010084:Oxidation-Reduction; D032306:Petunia / Q000201:enzymology* / Q000235:genetics; D010649:Phenylalanine / Q000737:chemistry* / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D027826:Rosa / Q000201:enzymology* / Q000235:genetics
chemical_list: D009097:Multienzyme Complexes; D010940:Plant Proteins; C513673:phenylacetaldehyde synthase, Pentunia hybrida; D010649:Phenylalanine; D000079:Acetaldehyde; C013192:phenylacetaldehyde