title: Type III polyketide synthase repertoire in Zingiberaceae: computational insights into the sequence, structure and evolution.
abstract: Zingiberaceae or 'ginger family' is the largest family in the order 'Zingiberales' with more than 1300 species in 52 genera, which are mostly distributed throughout Asia, tropical Africa and the native regions of America with their maximum diversity in Southeast Asia. Many of the members are important spice, medicinal or ornamental plants including ginger, turmeric, cardamom and kaempferia. These plants are distinguished for the highly valuable metabolic products, which are synthesised through phenylpropanoid pathway, where type III polyketide synthase is the key enzyme. In our present study, we used sequence, structural and evolutionary approaches to scrutinise the type III polyketide synthase (PKS) repertoire encoded in the Zingiberaceae family. Highly conserved amino acid residues in the sequence alignment and phylogram suggested strong relationships between the type III PKS members of Zingiberaceae. Sequence and structural level investigation of type III PKSs showed a small number of variations in the substrate binding pocket, leading to functional divergence among these PKS members. Molecular evolutionary studies indicate that type III PKSs within Zingiberaceae evolved under strong purifying selection pressure, and positive selections were rarely detected in the family. Structural modelling and protein-small molecule interaction studies on Zingiber officinale PKS 'a representative from Zingiberaceae' suggested that the protein is comparatively stable without much disorder and exhibited wide substrate acceptance.
authors.affiliation: Plant Molecular Biology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India.
authors.forename: Vijayanathan
authors.initials: V
authors.lastname: Mallika
authors.affiliation: Plant Molecular Biology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India.
authors.forename: Girija
authors.initials: G
authors.lastname: Aiswarya
authors.affiliation: Plant Molecular Biology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India.
authors.forename: Paily Thottathil
authors.initials: PT
authors.lastname: Gincy
authors.affiliation: Plant Molecular Biology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India.
authors.forename: Appukuttan
authors.initials: A
authors.lastname: Remakanthan
authors.affiliation: Plant Molecular Biology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India. evsoniya@rgcb.res.in.
authors.forename: Eppurathu Vasudevan
authors.initials: EV
authors.lastname: Soniya
mesh_terms: D000595:Amino Acid Sequence; D003198:Computer Simulation; D019143:Evolution, Molecular; D010802:Phylogeny; D048630:Polyketide Synthases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D030521:Zingiberaceae / Q000145:classification / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism
chemical_list: D048630:Polyketide Synthases
keywords: K a/K s analysis; Purifying selection; Type III polyketide synthase; Zingiberaceae