title: Sequence and Bioinformatic Analysis of Family 1 Glycoside Hydrolase (GH) 1 Gene from the Oomycete Pythium myriotylum Drechsler.
abstract: The oomycetous phytopathogen Pythium myriotylum secretes cellulases for growth/nutrition of the necrotroph. Cellulases are multi-enzyme system classified into different glycoside hydrolase (GH) families. The present study deals with identification and characterization of GH gene sequence from P. myriotylum by a PCR strategy using consensus primers. Cloning of the full-length gene sequence using genome walker strategy resulted in identification of 1230-bp P. myriotylum GH gene sequence, designated as PmGH1. Analysis revealed that PmGH1 encodes a predicted cytoplasmic 421 amino acid protein with an apparent molecular weight of 46.77 kDa and a theoretical pI of 8.11. Tertiary structure of the deduced amino acid sequence showed typical (α/β)8 barrel folding of family 1 GHs. Sequence characterization of PmGH1 identified the conserved active site residues, viz., Glu 181 and Glu 399, that function as acid-base catalyst and catalytically active nucleophile, respectively. Binding sites for N-acetyl-D-glucosamine (NAG) were revealed in the PmGH1 3D structure with Glu181 and Glu399 positioned on either side to form a catalytic pair. Phylogenetic analysis indicated a closer affiliation of PmGH1 with sequences of GH1 family. Results presented are first attempts providing novel insights into the evolutionary and functional perspectives of the identified P. myriotylum GH.
authors: School of Biotechnology, National Institute of Technology Calicut (NITC), Calicut, Kerala, India, aswati@nitc.ac.in.
authors: R Aswati
authors: RA
authors: Nair
authors: C
authors: C
authors: Geethu
authors: Amit
authors: A
authors: Sangwan
authors: P Padmesh
authors: PP
authors: Pillai
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D019295:Computational Biology; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000235:genetics*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011775:Pythium / Q000201:enzymology* / Q000235:genetics*; D016415:Sequence Alignment; D017421:Sequence Analysis; D012689:Sequence Homology, Nucleic Acid
chemical_list: D006026:Glycoside Hydrolases