Pyruvate formate lyase activating enzyme is a member of a novel superfamily of enzymes that utilize S-adenosylmethionine to initiate radical catalysis. This enzyme has been isolated with several different iron-sulfur clusters, but single turnover monitored by EPR has identified the [4Fe-4S](1+) cluster as the catalytically active cluster; this cluster is believed to be oxidized to the [4Fe-4S](...

Shapiro, Stanley K. (Argonne National Laboratory, Argonne, Ill.). Utilization of S-adenosylmethionine by microorganisms. J. Bacteriol. 83:169-174. 1962.-Two types of mutants of Aerobacter aerogenes that utilize S-adenosylmethionine for growth are described. One type also responds to methionine, 5'methylthioadenosine, or a combination of homocysteine and S-methylmethionine. The second type of mu...

The restriction endonuclease from Escherichia coli K specifically cleaves foreign DNA in the presence of S-adenosylmethionine, ATP, and Mg2+. The role of S-adenosylmethionine in this reaction has been studied by following the specific binding of the enzyme to unmodified DNA. The results indicate that S-adenosylmethionine acts as an allosteric effector. However, the rate-limiting step in the act...

The role of S-adenosyl-n-methionine as a methyl donor has been investigated in mammalian systems (1) and in microbial metabolism (2-4). In addition, the compound is involved in the formation of spermidine from putrescine (5). Information concerning the stability of S-adenosylmethionine in various enzymatic systems is a necessary prerequisite for studies concerning its role in group transfer. In...

S-Adenosylmethionine decarboxylase is a key enzyme for the synthesis of polyamines in mammals, plants and many other species that use aminopropyltransferases for this pathway. It catalyses the formation of S-adenosyl-1(methyl th io)-3-propylamine (decarboxyla ted S-adenosylmethionine), which is used as the aminopropyl donor. This is the sole function of decarboxylated S-adenosylmethionine. Its ...

The content of decarboxylated S-adenosylmethionine in rat tissues was found to be of the order of 0.9 to 2.5 nmol/g wet weight, about 2 to 4% of the content of S-adenosylmethionine. Three methods were used for determinations: separation by high pressure liquid chromatography followed by quantitation using UV absorbance, separation by paper electrophoresis after labeling with radioactive methion...

Methylglyoxal bis(guanylhydrazone) {1,1'-[(methylethanediylidene)-dinitrilo]diguanidine} is a very potent inhibitor of putrescine-activated S-adenosylmethionine decarboxylases from many different mammalian tissues, including sublines of mouse L1210 leukaemia that are resistant to the drug as well as sublines that are sensitive. The inhibition of purified rat ventral prostate S-adenosylmethionin...

This book represents the published proceedings of an international symposium on the biochemistry of adenosylmethionine held in Rome, Italy, in 1974. The introductory statement by the editors of this book best illustrates the significance of adenosylmethionine to all branches of biochemistry: "S-adenosylmethionine is probably second only to ATP in the variety of reactions for which it serves as ...

The sequence of a full-length cDNA coding for human liver S-adenosylmethionine synthetase has been determined. It spans 3217 nucleotides and encodes a protein of 395 amino acid residues, with a calculated molecular mass of 43,647 Da. The structural features deduced from the amino acid sequence show a close similarity to those of the rat liver enzyme. The liver-specific S-adenosylmethionine synt...