Sequence and Bioinformatic Analysis of Family 1 Glycoside Hydrolase (GH) 1 Gene from the Oomycete Pythium myriotylum Drechsler
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.
KeywordsCell wall degrading enzymes Family 1 GH Genome walker Oomycete Pythium
The present research was supported by Faculty Research Grant (FRG) scheme (No. NITC/Dean(C&SR)/FRG10/0112) of NITC. PP thanks the Director of JNTBGRI, Kerala, India, for the research facilities extended.
Compliance with Ethical Standards
We hereby certify that the communicated manuscript is not submitted to any other journal for simultaneous consideration, nor been published previously (partly or in full). Furthermore, authors declare that they have no conflict of interest concerning this article. The investigations reported in the present manuscript do not involve any clinical studies engaging human participants or animals.
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