GrainGenes Reference Report: PMB-13-31
Reference
PMB-13-31
Title
Purification of 1-3-beta glucan endohydrolase isoenzyme II from germinated barley and determination of its primary structure from a complementary DNA clone
Journal
Plant Molecular Biology
Year
1989
Volume
13
Pages
31-42
Author
Hoj PB Hartman DJ Morrice NA Doan DNP Fincher GB
Type
Article
Language
English
Abstract
A (1 .fwdarw. 3)-.beta.-D-glucan 3-glucanohydrolase (EC 3.2.1.39) of apparent Mr 32000, designated GII, has been purified from germinated barley grain and characterized. The isoenzyme is resolved from a previously purified isoenzyme (GI) on the basis of differences in their isoelectric points; (1 .fwdarw. 3)-.beta.-glucanases GI and GII have pI values of 8.6 and .gtoreq. 10.0, respectively. Comparison of the sequences of their 40 NH2-terminal amino acids reveals 68% positional identity. A 1265 nucleotide pair cDNA encoding (1 .fwdarw. 3)-.beta.-glucanase isoenzyme GII has been isolated from a library prepared with mRNA of 2-day germinated barley scutella. Nucleotide sequence analysis of the cDNA has enabled the complete primary structured of the 306 amino acid (1 .fwdarw. 3)-.beta.-glucanase to be deduced, together with that of a putative NH2-terminal signal peptide of 28 amino acid residues. The (1 .fwdarw. 3)-.beta.-glucanase cDNA is characterized by a high (G + C) content, which reflects a strong bias for the use of G or C in the wobble base position of codons. The amino acid sequence of the (1 .fwdarw. 3)-.beta.-glucanase shows highly conserved internal domains and 52% overall positional identity with barley (1 .fwdarw. 3, 1 .fwdarw. 4)-.beta.-glucanase isoenzyme EII, an enzyme of related but quite distinct substrate specificity. Thus, the (1 .fwdarw. 3)-.beta.-glucanases, which may provide a degree of protection against microbial invasion of germinated barley grain through ability to degrade fungal cell wall polysaccharides, appear to share a common evolutionary origin with the (1 .fwdarw. 3, 1 .fwdarw. 4)-.beta.-glucanases, which function to depolymerize endosperm cell walls in the germinated grain.
Probe
lambda-3
Keyword
Agriculture
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GrainGenes is a product of the Agricultural Research Service of the US Department of Agriculture.
GrainGenes Reference Report: PMB-13-31
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GrainGenes is a product of the Agricultural Research Service of the US Department of Agriculture. | |||