Geobacillus stearothermophilus: A species of GRAM-POSITIVE ENDOSPORE-FORMING BACTERIA in the family BACILLACEAE, found in soil, hot springs, Arctic waters, ocean sediments, and spoiled food products.Bacillaceae: A family of bacteria which produce endospores. They are mostly saprophytes from soil, but a few are insect or animal parasites or pathogens.Geobacillus: A genus of gram-positive, endospore-forming, thermophilic bacteria in the family BACILLACEAE.Bacterial Proteins: Proteins found in any species of bacterium.Glycoside HydrolasesHot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Catalytic Domain: The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Crystallization: The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Bacillus: A genus of BACILLACEAE that are spore-forming, rod-shaped cells. Most species are saprophytic soil forms with only a few species being pathogenic.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Bacillales: An order of gram-positive bacteria in the class Bacilli, phylum Firmicutes.Anoxybacillus: A genus of GRAM-POSITIVE ENDOSPORE-FORMING BACTERIA in the family Bacillaceae. Most species have been isolated from HOT SPRINGS.Enzyme Stability: The extent to which an enzyme retains its structural conformation or its activity when subjected to storage, isolation, and purification or various other physical or chemical manipulations, including proteolytic enzymes and heat.Spores, Bacterial: Heat and stain resistant, metabolically inactive bodies formed within the vegetative cells of bacteria of the genera Bacillus and Clostridium.Tyrosine-tRNA Ligase: An enzyme that activates tyrosine with its specific transfer RNA. EC 22.214.171.124.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.