Plant phenylacetaldehyde synthase is a bifunctional homotetrameric enzyme that catalyzes phenylalanine decarboxylation and oxidation.
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.
Kaminaga
Yasuhisa
Y
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907-2010, USA.
Schnepp
Jennifer
J
Peel
Greg
G
Kish
Christine M
CM
Ben-Nissan
Gili
G
Weiss
David
D
Orlova
Irina
I
Lavie
Orly
O
Rhodes
David
D
Wood
Karl
K
Porterfield
D Marshall
DM
Cooper
Arthur J L
AJ
Schloss
John V
JV
Pichersky
Eran
E
Vainstein
Alexander
A
Dudareva
Natalia
N
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
D009097:Multienzyme Complexes; D010940:Plant Proteins; C513673:phenylacetaldehyde synthase, Pentunia hybrida; D010649:Phenylalanine; D000079:Acetaldehyde; C013192:phenylacetaldehyde