Folate reductase and specific dihydrofolate reductase activities of the amethopterin-sensitive Streptococcus faecium var. durans.
نویسندگان
چکیده
Preliminary evidence is presented that indicates that the dihydrofolate reductase activity of amethopterin-sensitive Streptococcus faecium var. durans ATCC 8043 is separable into two dihydrofolate reductases, one of which also reduces folate.
منابع مشابه
Dihydrofolate Reductase of Streptococcus f aecium II. PURIFICATION AND SOME PROPERTIES OF TWO DIHYDROFOLATE REDUCTASES FROM THE AMETHOPTERIN-RESISTANT
From a single amethopterin-resistant organism, Streptococcus faecium var. durans strain A, two different dihydrofolate reductases have been obtained as essentially homogeneous proteins in good yield. One of the reductases has a similar substrate specificity and turnover number (about 8000 moles per min per mole of enzyme) to the single reductase found in the amethopterin-sensitive strain of S. ...
متن کاملDihydrofolate Reductase of Streptococcus f aecium
From a single amethopterin-resistant organism, Streptococcus faecium var. durans strain A, two different dihydrofolate reductases have been obtained as essentially homogeneous proteins in good yield. One of the reductases has a similar substrate specificity and turnover number (about 8000 moles per min per mole of enzyme) to the single reductase found in the amethopterin-sensitive strain of S. ...
متن کاملThe Structure of Dihydrofolate Reductase I. INACTIVATION OF BACTERIAL DIHYDROFOLATE REDUCTASE CONCOMITANT WITH MODIFICATION OF A METHIONINE RESIDUE AT THE ACTIVE SITE*
Carboxymethylation by iodoacetate of dihydrofolate reductase from the amethopterin-resistant mutant Streptococcus faecium var. Durans strain A leads to a loss of enzymic activity. Amino acid analysis showed that methionine is the only amino acid residue significantly affected by iodoacetate under the experimental conditions, and this was confirmed by the use of [ll’C]iodoacetate and ion exchang...
متن کاملThe structure of dihydrofolate reductase. I. Inactivation of bacterial dihydrofolate reductase concomitant with modification of a methionine residue at the active site.
Carboxymethylation by iodoacetate of dihydrofolate reductase from the amethopterin-resistant mutant Streptococcus faecium var. Durans strain A leads to a loss of enzymic activity. Amino acid analysis showed that methionine is the only amino acid residue significantly affected by iodoacetate under the experimental conditions, and this was confirmed by the use of [1-14-C]iodoacetate and ion excha...
متن کاملDihydrofolate Reductase in Genotypically Distinguishable Amethopterin-resistant Diplococcus Pneumoniae.
Mutation to amethopterin(4-amino-lo-methylpteroylglutamic acid) resistance in Diplococcus pneumoniae has been shown (1) to occur in two distinct and remotely situated regions of the deoxyribonucleic acid. Comparative growth and cross-resistance studies, also reported at that time, suggested that these genetic regions were also biochemically distinguishable. During investigations seeking to iden...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of bacteriology
دوره 100 1 شماره
صفحات -
تاریخ انتشار 1969