@article {1413, title = {Bioinformatic and biochemical analysis of a novel maltose-forming α-amylase of the GH57 family in the hyperthermophilic archaeon Thermococcus sp. CL1.}, journal = {Enzyme Microb Technol}, volume = {60}, year = {2014}, month = {2014 Jun 10}, pages = {9-15}, 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.
}, issn = {1879-0909}, doi = {10.1016/j.enzmictec.2014.03.009}, author = {Jeon, Eun-Jung and Jung, Jong-Hyun and Seo, Dong-Ho and Jung, Dong-Hyun and Holden, James F and Park, Cheon-Seok} } @article {1200, title = {Complete genome sequence of hyperthermophilic archaeon Thermococcus sp. ES1.}, journal = {J Biotechnol}, volume = {174C}, year = {2014}, month = {2014 Jan 25}, pages = {14-15}, abstract = {Thermococcus sp. strain ES1 is an anaerobic, hyperthermophilic archaeon from a hydrothermal vent that catabolizes sugars and peptides and produces H2S from S{\textdegree}, H2, acetate and CO2 as its primary metabolites. We present the complete genome sequence of this strain (1,957,742bp) with a focus on its substrate utilization and metabolite production capabilities. The sequence will contribute to the development of heterotrophic archaea for bioenergy production and biogeochemical modeling in hydrothermal environments.
}, issn = {1873-4863}, doi = {10.1016/j.jbiotec.2014.01.022}, author = {Jung, Jong-Hyun and Kim, You-Tae and Jeon, Eun-Jung and Seo, Dong-Ho and Hensley, Sarah A and Holden, James F and Lee, Ju-Hoon and Park, Cheon-Seok} }