@article {1412,
	title = {Structural features underlying the selective cleavage of a novel exo-type maltose-forming amylase from Pyrococcus sp. ST04.},
	journal = {Acta Crystallogr D Biol Crystallogr},
	volume = {70},
	year = {2014},
	month = {2014 Jun},
	pages = {1659-68},
	abstract = {<p>A novel maltose-forming \&alpha;-amylase (PSMA) was recently found in the hyperthermophilic archaeon Pyrococcus sp. ST04. This enzyme shows \&lt;13\% amino-acid sequence identity to other known \&alpha;-amylases and displays a unique enzymatic property in that it hydrolyzes both \&alpha;-1,4-glucosidic and \&alpha;-1,6-glucosidic linkages of substrates, recognizing only maltose units, in an exo-type manner. Here, the crystal structure of PSMA at a resolution of 1.8 \&Aring; is reported, showing a tight ring-shaped tetramer with monomers composed of two domains: an N-domain (amino acids 1-341) with a typical GH57 family (\&beta;/\&alpha;)7-barrel fold and a C-domain (amino acids 342-597) composed of \&alpha;-helical bundles. A small closed cavity observed in proximity to the catalytic residues Glu153 and Asp253 at the domain interface has the appropriate volume and geometry to bind a maltose unit, accounting for the selective exo-type maltose hydrolysis of the enzyme. A narrow gate at the putative subsite +1 formed by residue Phe218 and Phe452 is essential for specific cleavage of glucosidic bonds. The closed cavity at the active site is connected to a short substrate-binding channel that extends to the central hole of the tetramer, exhibiting a geometry that is significantly different from classical maltogenic amylases or \&beta;-amylases. The structural features of this novel exo-type maltose-forming \&alpha;-amylase provide a molecular basis for its unique enzymatic characteristics and for its potential use in industrial applications and protein engineering.</p>
},
	keywords = {Amylases, Catalytic Domain, Maltose, Models, Molecular, Mutagenesis, Site-Directed, Protein Conformation, Proteolysis, Pyrococcus, Substrate Specificity},
	issn = {1399-0047},
	doi = {10.1107/S1399004714006567},
	author = {Park, Kwang-Hyun and Jung, Jong-Hyun and Park, Sung-Goo and Lee, Myeong-Eun and Holden, James F and Park, Cheon-Seok and Woo, Eui-Jeon}
}
@article {1207,
	title = {Complete genome sequence of the hyperthermophilic archaeon Pyrococcus sp. strain ST04, isolated from a deep-sea hydrothermal sulfide chimney on the Juan de Fuca Ridge.},
	journal = {J Bacteriol},
	volume = {194},
	year = {2012},
	month = {2012 Aug},
	pages = {4434-5},
	abstract = {<p>Pyrococcus sp. strain ST04 is a hyperthermophilic, anaerobic, and heterotrophic archaeon isolated from a deep-sea hydrothermal sulfide chimney on the Endeavour Segment of the Juan de Fuca Ridge in the northeastern Pacific Ocean. To further understand the distinct characteristics of this archaeon at the genome level (polysaccharide utilization at high temperature and ATP generation by a Na(+) gradient), the genome of strain ST04 was completely sequenced and analyzed. Here, we present the complete genome sequence analysis results of Pyrococcus sp. ST04 and report the major findings from the genome annotation, with a focus on its saccharolytic and metabolite production potential.</p>},
	keywords = {Adenosine Triphosphate, Anaerobiosis, DNA, Archaeal, Genome, Archaeal, Heterotrophic Processes, Hydrothermal Vents, Molecular Sequence Data, Pacific Ocean, Polysaccharides, Pyrococcus, Seawater, Sequence Analysis, DNA, Sodium Chloride, Sulfides},
	issn = {1098-5530},
	doi = {10.1128/JB.00824-12},
	author = {Jung, Jong-Hyun and Lee, Ju-Hoon and Holden, James F and Seo, Dong-Ho and Shin, Hakdong and Kim, Hae-Yeong and Kim, Wooki and Ryu, Sangryeol and Park, Cheon-Seok}
}
