Bioinformatic and biochemical analysis of a novel maltose-forming α-amylase of the GH57 family in the hyperthermophilic archaeon Thermococcus sp. CL1.

TitleBioinformatic and biochemical analysis of a novel maltose-forming α-amylase of the GH57 family in the hyperthermophilic archaeon Thermococcus sp. CL1.
Publication TypeJournal Article
Year of Publication2014
AuthorsJeon E-J, Jung J-H, Seo D-H, Jung D-H, Holden JF, Park C-S
JournalEnzyme Microb Technol
Volume60
Pagination9-15
Date Published2014 Jun 10
ISSN1879-0909
Abstract

Maltose-forming α-amylase is a glycoside hydrolase family 57 (GH57) member that is unique because it displays dual hydrolysis activity toward α-1,4- and α-1,6-glycosidic linkages and only recognizes maltose. This enzyme was previously identified only in Pyrococcus sp. ST04 (PSMA); however, we recently found two homologs subgroups in Thermococcus species. One subgroup (subgroup A) showed relatively high amino acid sequence similarity to PSMA (>71%), while the other subgroup (subgroup B) showed lower homology with PSMA (<59%). To characterize the subgroup B maltose-forming α-amylase from Thermococcus species (TCMA), we cloned the CL1_0868 gene from Thermococcus sp. CL1 and then successfully expressed the gene in Escherichia coli. Although TCMA has a different oligomeric state relative to PSMA, TCMA showed similar substrate specificity. However, TCMA was shown to hydrolyze maltooligosaccharides more easily than PSMA. Also, TCMA displayed different optimum conditions depending on the glycosidic linkage of the substrate. TCMA had the highest activity at 85°C and at pH 5.0 for α-1,4-glycosidic linkage hydrolysis whereas it showed its maximal activity to cleave α-1,6-glycosidic linkages at 98°C and pH 6.0.

DOI10.1016/j.enzmictec.2014.03.009
Alternate JournalEnzyme Microb. Technol.
PubMed ID24835094