Biomaterial Database

The outB gene of Bacillus subtilis codes for NAD synthetase. 1995

C Nessi, and A M Albertini, and M L Speranza, and A Galizzi

Dipartimenti di Genetica e Microbiologia, Università di Pavia, Italy.

The outB gene of Bacillus subtilis is involved in spore germination and outgrowth and is essential for growth. The OutB protein was obtained by expression in Escherichia coli and purified to apparent homogeneity. Here we report experiments showing that OutB is a NH3-dependent NAD synthetase, the enzyme that catalyzes the final reaction in the biosynthesis of NAD. The enzyme is composed of two identical subunits of 30,240 Da and is NH3-dependent, whereas glutamine is inefficient as an amide donor. The NAD synthetase is highly resistant to heat, with a half-time of inactivation at 100 degrees C of 13 min. A mutant NAD synthetase was purified from a B. subtilis strain temperature-sensitive during spore germination and outgrowth. The mutant enzyme was 200 times less active than the wild-type one, with a lower temperature optimum and a non-hyperbolic kinetic versus NH4+. The time course of synthesis of OutB showed that synthesis of the enzyme started during germination and outgrowth, and reached the highest level at the end of exponential growth. The enzyme could be recovered from dormant spores.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008025	Ligases	A class of enzymes that catalyze the formation of a bond between two substrate molecules, coupled with the hydrolysis of a pyrophosphate bond in ATP or a similar energy donor. (Dorland, 28th ed) EC 6.	Ligase,Synthetases,Synthetase
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004795	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.	Enzyme Stabilities,Stabilities, Enzyme,Stability, Enzyme
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005798	Genes, Bacterial	The functional hereditary units of BACTERIA.	Bacterial Gene,Bacterial Genes,Gene, Bacterial
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
D001412	Bacillus subtilis	A species of gram-positive bacteria that is a common soil and water saprophyte.	Natto Bacteria,Bacillus subtilis (natto),Bacillus subtilis subsp. natto,Bacillus subtilis var. natto
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial