Bioinformatics Analysis of Phenylacetaldehyde Synthase (PAAS), a Protein Involved in Flower Scent Production, in Rose

Akbar Karami Samira Jandoust

doi:10.4172/2161-0398.1000170

Abstract

Rose flowers produce and emit the aromatic volatiles 2-phenylacetaldehyde (PAA) and 2-phenylethanol (2-PE), which have a distinctive flowery/rose-like scent. Previous studies of rose have shown that, similar to Petunia flowers, PAA is formed from L-phenylalanine via pyridoxal-5'-phosphate-dependent L-aromatic amino acid decarboxylase. Rosa phenylacetaldehyde synthase sequence (RhPAAS) is homologous to Petunia phenylacetaldehyde synthase (PhPAAS). Since there is not much experimental data available about different structural properties of that PAAS protein, in the present investigation, we studied the different structural properties of the PAAS protein in petunia and rose using bioinformatics tools. The features of the first, secondary and tertiary structures of this protein were compared between Petunia and Rose. The results indicated that the frequency of negatively charged, Leucine, and frequency of the Ser-Leu, Pro-Glu , Phe-Ser and the, Thr-Thr dipeptides in petunia are more than those in Rose. In contrast, in petunia, the frequencies of hydrophobic and hydrophilic residues, α-helix, β-sheet, β-strands of petunia are lower than those in rose. The features achieved in this study may also provide useful clues for designing scent production pathways using protein engineering techniques.

Highlights

Phenyl acetaldehyde (PHA), 2-phenylethanol (2-PE), and its acetate ester are important scent compounds in numerous flowers, including petunias and roses
phenylacetaldehyde synthase (PAAS) by alignment is homologous with Aromatic L-amino acid decarboxylase (AADC) catalyzes the second enzymatic step in synthesis of the neurotransmitters dopamine and serotonin, which are found in neurons of all animals [4]
The results indicated that, the major aromatic amino acid for PAAS (Phe) in Petunia is more than Rosa

Summary

Introduction

Phenyl acetaldehyde (PHA), 2-phenylethanol (2-PE), and its acetate ester are important scent compounds in numerous flowers, including petunias and roses. They contribute to the aromas of tomato, grape, and tamarind, fruits and to the flavor of tea. PAAS is the first PLP enzyme to be described that, in its native state, catalyzes the stoichiometric oxidative decarboxylation of an L-amino acid substrate (Figure 1) [1,2,3,4,5,6,7,8,9,10,11,12,13]. PAAS by alignment is homologous with Aromatic L-amino acid decarboxylase (AADC) catalyzes the second enzymatic step in synthesis of the neurotransmitters dopamine and serotonin, which are found in neurons of all animals [4]. The Arabidopsis thaliana genome includes two genes, At2g20340 and At4g28680, encoding pyridoxal 5′-phosphate-dependent AADCs with high homology to PhPAAS [8]

Methods

Results

Conclusion