Biomaterial Database

The purification and characterization of delta 5-3-ketosteroid isomerase from Pseudomonas putida, a cysteine-containing isomerase. 1980

S B Smith, and J W Richards, and W F Benisek

A delta 5-3-ketosteroid isomerase (EC 5.3.3.1) has been isolated from Pseudomonas putida Biotype B and purified to homogeneity. This previously undescribed steroid isomerase resembles that isolated from Pseudomonas testosteroni (Talalay, P., and Wang, V.S. (1955) Biochim. Biophys. Acta 18, 300-301). The enzyme is induced by various steroids, has a subunit molecular weight of 13,750 +/- 250, a pI of 4.8 +/- 0.1 has a specific activity of 40,000 units/mg, using 5-androstene-3,17-dione as the substrate. The amino acid composition of the enzyme subunit is Lys 2, His 2, Arg 8, Asp 11, Thr 5, Ser 4, Glu 17, Pro 8, Gly 12, Ala 12, Val 10, Met 5, Ile 6, Leu 8, Tyr 4, Phe 4, and Cys 4. The amino acid sequence has been determined for the NH2-terminal 50 residues. This portion of the polypeptide chain is approximately 47% homologous with the amino acid sequence of the first 50 residues of the delta 5-3-ketosteroid isomerase from P. testosteroni. The amino acid sequence of residues 33 to 41 of the P. putida isomerase is identical with the region Ala 31 through Pro 39 in the P. testosteroni enzyme. Residue 40 of the P. putida enzyme is aspartic acid and corresponds in the sequence to Asp 38 of the P. testosteroni isomerase, which has been shown to be essential for enzymatic activity (Ogez, J.R., Tivol, W.F., and Benisek, W.F. (1977) J. Biol. Chem. 252, 6151-6155).

UI	MeSH Term	Description	Entries
D007535	Isomerases	A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.(from Dorland, 28th ed) EC 5.	Isomerase
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D011549	Pseudomonas	A genus of gram-negative, aerobic, rod-shaped bacteria widely distributed in nature. Some species are pathogenic for humans, animals, and plants.	Chryseomonas,Pseudomona,Flavimonas
D003545	Cysteine	A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.	Cysteine Hydrochloride,Half-Cystine,L-Cysteine,Zinc Cysteinate,Half Cystine,L Cysteine
D000595	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.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
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
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D013251	Steroid Isomerases	Enzymes that catalyze the transposition of double bond(s) in a steroid molecule. EC 5.3.3.	3-Ketosteroid Isomerases,3-Oxosteroid Isomerases,3 Ketosteroid Isomerases,3 Oxosteroid Isomerases,Isomerases, 3-Ketosteroid,Isomerases, 3-Oxosteroid,Isomerases, Steroid