In Silico Cloning and Bioinformatic Analysis of β-1,3-glucanase Gene(ScBG) from sugarcane(Saccharum spp.)

Based on in silico cloning, a novel sugarcane β-1,3-glucanase gene, termed as ScBG, was identified by using β-1,3-glucanase cDNA sequence of Sorghum bicolor as a probe to search the sugarcane ESTs database. Several characters of ScBG protein, including the composition of amino acid sequence, physical and chemical properties, transmembrane domain, coiled coil, subcellular localization, signal peptide, functional domain, and secondary and tertiary structure were predicted and analyzed by bioinformatics tools. The results showed that this ScBG gene, which was 1 270 bp long, contained a complete ORF of 1 011 bp. It encoded the 336 amino acid polypeptide with a molecular weight of 38.4 KD and the isoelectric point of 4.98. Besides, the protein was a stable secretory protein and was most likely to be an inducer-released extracellular acid glucanase, credibility to the highest level 1. ScBG belonged to glycoside hydrolase family 17 and contained a N-terminal signal peptide and 2 main function domain. At the loci of 7~29 amino acids, ScBG contained transmembrane signal area while at the loci of 31~321, it contained glycoside hydrolase structure domain specific in family 17. When comparing ScBG homologous amino acid sequences among sugarcane and other plant species, the result showed that ScBG protein had the highest similarity with that of Sorghum bicolor, which was 79.82%. This study aims to provide the basis for the molecular cloning, functional analysis and application of this gene in the future.